ClabureDB: Classified Bug-Reports Database

   #define VERSION "0.23"
   /* ns83820.c by Benjamin LaHaise with contributions.
    *
    * Questions/comments/discussion to linux-ns83820@kvack.org.
    *
    * $Revision: 1.34.2.23 $
    *
    * Copyright 2001 Benjamin LaHaise.
    * Copyright 2001, 2002 Red Hat.
   *
   * Mmmm, chocolate vanilla mocha...
   *
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   *
   * ChangeLog
   * =========
   *        20010414        0.1 - created
   *        20010622        0.2 - basic rx and tx.
   *        20010711        0.3 - added duplex and link state detection support.
   *        20010713        0.4 - zero copy, no hangs.
   *                        0.5 - 64 bit dma support (davem will hate me for this)
   *                            - disable jumbo frames to avoid tx hangs
   *                            - work around tx deadlocks on my 1.02 card via
   *                              fiddling with TXCFG
   *        20010810        0.6 - use pci dma api for ringbuffers, work on ia64
   *        20010816        0.7 - misc cleanups
   *        20010826        0.8 - fix critical zero copy bugs
   *                        0.9 - internal experiment
   *        20010827        0.10 - fix ia64 unaligned access.
   *        20010906        0.11 - accept all packets with checksum errors as
   *                               otherwise fragments get lost
   *                             - fix >> 32 bugs
   *                        0.12 - add statistics counters
   *                             - add allmulti/promisc support
   *        20011009        0.13 - hotplug support, other smaller pci api cleanups
   *        20011204        0.13a - optical transceiver support added
   *                                by Michael Clark <michael@metaparadigm.com>
   *        20011205        0.13b - call register_netdev earlier in initialization
   *                                suppress duplicate link status messages
   *        20011117         0.14 - ethtool GDRVINFO, GLINK support from jgarzik
   *        20011204         0.15        get ppc (big endian) working
   *        20011218        0.16        various cleanups
   *        20020310        0.17        speedups
   *        20020610        0.18 -        actually use the pci dma api for highmem
   *                             -        remove pci latency register fiddling
   *                        0.19 -        better bist support
   *                             -        add ihr and reset_phy parameters
   *                             -        gmii bus probing
   *                             -        fix missed txok introduced during performance
   *                                tuning
   *                        0.20 -        fix stupid RFEN thinko.  i am such a smurf.
   *        20040828        0.21 -        add hardware vlan accleration
   *                                by Neil Horman <nhorman@redhat.com>
   *        20050406        0.22 -        improved DAC ifdefs from Andi Kleen
   *                             -        removal of dead code from Adrian Bunk
   *                             -        fix half duplex collision behaviour
   * Driver Overview
   * ===============
   *
   * This driver was originally written for the National Semiconductor
   * 83820 chip, a 10/100/1000 Mbps 64 bit PCI ethernet NIC.  Hopefully
   * this code will turn out to be a) clean, b) correct, and c) fast.
   * With that in mind, I'm aiming to split the code up as much as
   * reasonably possible.  At present there are X major sections that
   * break down into a) packet receive, b) packet transmit, c) link
   * management, d) initialization and configuration.  Where possible,
   * these code paths are designed to run in parallel.
   *
   * This driver has been tested and found to work with the following
   * cards (in no particular order):
   *
   *        Cameo                SOHO-GA2000T        SOHO-GA2500T
   *        D-Link                DGE-500T
   *        PureData        PDP8023Z-TG
   *        SMC                SMC9452TX        SMC9462TX
   *        Netgear                GA621
   *
   * Special thanks to SMC for providing hardware to test this driver on.
   *
   * Reports of success or failure would be greatly appreciated.
   */
  //#define dprintk                printk
  #define dprintk(x...)                do { } while (0)
  
  #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/dma-mapping.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/delay.h>
 #include <linux/workqueue.h>
 #include <linux/init.h>
 #include <linux/ip.h>        /* for iph */
 #include <linux/in.h>        /* for IPPROTO_... */
 #include <linux/compiler.h>
 #include <linux/prefetch.h>
 #include <linux/ethtool.h>
 #include <linux/timer.h>
 #include <linux/if_vlan.h>
 #include <linux/rtnetlink.h>
 #include <linux/jiffies.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
 #define DRV_NAME "ns83820"
 
 /* Global parameters.  See module_param near the bottom. */
 static int ihr = 2;
 static int reset_phy = 0;
 static int lnksts = 0;                /* CFG_LNKSTS bit polarity */
 
 /* Dprintk is used for more interesting debug events */
 #undef Dprintk
 #define        Dprintk                        dprintk
 
 /* tunables */
 #define RX_BUF_SIZE        1500        /* 8192 */
 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 #define NS83820_VLAN_ACCEL_SUPPORT
 #endif
 
 /* Must not exceed ~65000. */
 #define NR_RX_DESC        64
 #define NR_TX_DESC        128
 
 /* not tunable */
 #define REAL_RX_BUF_SIZE (RX_BUF_SIZE + 14)        /* rx/tx mac addr + type */
 
 #define MIN_TX_DESC_FREE        8
 
 /* register defines */
 #define CFGCS                0x04
 
 #define CR_TXE                0x00000001
 #define CR_TXD                0x00000002
 /* Ramit : Here's a tip, don't do a RXD immediately followed by an RXE
  * The Receive engine skips one descriptor and moves
  * onto the next one!! */
 #define CR_RXE                0x00000004
 #define CR_RXD                0x00000008
 #define CR_TXR                0x00000010
 #define CR_RXR                0x00000020
 #define CR_SWI                0x00000080
 #define CR_RST                0x00000100
 
 #define PTSCR_EEBIST_FAIL       0x00000001
 #define PTSCR_EEBIST_EN         0x00000002
 #define PTSCR_EELOAD_EN         0x00000004
 #define PTSCR_RBIST_FAIL        0x000001b8
 #define PTSCR_RBIST_DONE        0x00000200
 #define PTSCR_RBIST_EN          0x00000400
 #define PTSCR_RBIST_RST         0x00002000
 
 #define MEAR_EEDI                0x00000001
 #define MEAR_EEDO                0x00000002
 #define MEAR_EECLK                0x00000004
 #define MEAR_EESEL                0x00000008
 #define MEAR_MDIO                0x00000010
 #define MEAR_MDDIR                0x00000020
 #define MEAR_MDC                0x00000040
 
 #define ISR_TXDESC3        0x40000000
 #define ISR_TXDESC2        0x20000000
 #define ISR_TXDESC1        0x10000000
 #define ISR_TXDESC0        0x08000000
 #define ISR_RXDESC3        0x04000000
 #define ISR_RXDESC2        0x02000000
 #define ISR_RXDESC1        0x01000000
 #define ISR_RXDESC0        0x00800000
 #define ISR_TXRCMP        0x00400000
 #define ISR_RXRCMP        0x00200000
 #define ISR_DPERR        0x00100000
 #define ISR_SSERR        0x00080000
 #define ISR_RMABT        0x00040000
 #define ISR_RTABT        0x00020000
 #define ISR_RXSOVR        0x00010000
 #define ISR_HIBINT        0x00008000
 #define ISR_PHY                0x00004000
 #define ISR_PME                0x00002000
 #define ISR_SWI                0x00001000
 #define ISR_MIB                0x00000800
 #define ISR_TXURN        0x00000400
 #define ISR_TXIDLE        0x00000200
 #define ISR_TXERR        0x00000100
 #define ISR_TXDESC        0x00000080
 #define ISR_TXOK        0x00000040
 #define ISR_RXORN        0x00000020
 #define ISR_RXIDLE        0x00000010
 #define ISR_RXEARLY        0x00000008
 #define ISR_RXERR        0x00000004
 #define ISR_RXDESC        0x00000002
 #define ISR_RXOK        0x00000001
 
 #define TXCFG_CSI        0x80000000
 #define TXCFG_HBI        0x40000000
 #define TXCFG_MLB        0x20000000
 #define TXCFG_ATP        0x10000000
 #define TXCFG_ECRETRY        0x00800000
 #define TXCFG_BRST_DIS        0x00080000
 #define TXCFG_MXDMA1024        0x00000000
 #define TXCFG_MXDMA512        0x00700000
 #define TXCFG_MXDMA256        0x00600000
 #define TXCFG_MXDMA128        0x00500000
 #define TXCFG_MXDMA64        0x00400000
 #define TXCFG_MXDMA32        0x00300000
 #define TXCFG_MXDMA16        0x00200000
 #define TXCFG_MXDMA8        0x00100000
 
 #define CFG_LNKSTS        0x80000000
 #define CFG_SPDSTS        0x60000000
 #define CFG_SPDSTS1        0x40000000
 #define CFG_SPDSTS0        0x20000000
 #define CFG_DUPSTS        0x10000000
 #define CFG_TBI_EN        0x01000000
 #define CFG_MODE_1000        0x00400000
 /* Ramit : Dont' ever use AUTO_1000, it never works and is buggy.
  * Read the Phy response and then configure the MAC accordingly */
 #define CFG_AUTO_1000        0x00200000
 #define CFG_PINT_CTL        0x001c0000
 #define CFG_PINT_DUPSTS        0x00100000
 #define CFG_PINT_LNKSTS        0x00080000
 #define CFG_PINT_SPDSTS        0x00040000
 #define CFG_TMRTEST        0x00020000
 #define CFG_MRM_DIS        0x00010000
 #define CFG_MWI_DIS        0x00008000
 #define CFG_T64ADDR        0x00004000
 #define CFG_PCI64_DET        0x00002000
 #define CFG_DATA64_EN        0x00001000
 #define CFG_M64ADDR        0x00000800
 #define CFG_PHY_RST        0x00000400
 #define CFG_PHY_DIS        0x00000200
 #define CFG_EXTSTS_EN        0x00000100
 #define CFG_REQALG        0x00000080
 #define CFG_SB                0x00000040
 #define CFG_POW                0x00000020
 #define CFG_EXD                0x00000010
 #define CFG_PESEL        0x00000008
 #define CFG_BROM_DIS        0x00000004
 #define CFG_EXT_125        0x00000002
 #define CFG_BEM                0x00000001
 
 #define EXTSTS_UDPPKT        0x00200000
 #define EXTSTS_TCPPKT        0x00080000
 #define EXTSTS_IPPKT        0x00020000
 #define EXTSTS_VPKT        0x00010000
 #define EXTSTS_VTG_MASK        0x0000ffff
 
 #define SPDSTS_POLARITY        (CFG_SPDSTS1 | CFG_SPDSTS0 | CFG_DUPSTS | (lnksts ? CFG_LNKSTS : 0))
 
 #define MIBC_MIBS        0x00000008
 #define MIBC_ACLR        0x00000004
 #define MIBC_FRZ        0x00000002
 #define MIBC_WRN        0x00000001
 
 #define PCR_PSEN        (1 << 31)
 #define PCR_PS_MCAST        (1 << 30)
 #define PCR_PS_DA        (1 << 29)
 #define PCR_STHI_8        (3 << 23)
 #define PCR_STLO_4        (1 << 23)
 #define PCR_FFHI_8K        (3 << 21)
 #define PCR_FFLO_4K        (1 << 21)
 #define PCR_PAUSE_CNT        0xFFFE
 
 #define RXCFG_AEP        0x80000000
 #define RXCFG_ARP        0x40000000
 #define RXCFG_STRIPCRC        0x20000000
 #define RXCFG_RX_FD        0x10000000
 #define RXCFG_ALP        0x08000000
 #define RXCFG_AIRL        0x04000000
 #define RXCFG_MXDMA512        0x00700000
 #define RXCFG_DRTH        0x0000003e
 #define RXCFG_DRTH0        0x00000002
 
 #define RFCR_RFEN        0x80000000
 #define RFCR_AAB        0x40000000
 #define RFCR_AAM        0x20000000
 #define RFCR_AAU        0x10000000
 #define RFCR_APM        0x08000000
 #define RFCR_APAT        0x07800000
 #define RFCR_APAT3        0x04000000
 #define RFCR_APAT2        0x02000000
 #define RFCR_APAT1        0x01000000
 #define RFCR_APAT0        0x00800000
 #define RFCR_AARP        0x00400000
 #define RFCR_MHEN        0x00200000
 #define RFCR_UHEN        0x00100000
 #define RFCR_ULM        0x00080000
 
 #define VRCR_RUDPE        0x00000080
 #define VRCR_RTCPE        0x00000040
 #define VRCR_RIPE        0x00000020
 #define VRCR_IPEN        0x00000010
 #define VRCR_DUTF        0x00000008
 #define VRCR_DVTF        0x00000004
 #define VRCR_VTREN        0x00000002
 #define VRCR_VTDEN        0x00000001
 
 #define VTCR_PPCHK        0x00000008
 #define VTCR_GCHK        0x00000004
 #define VTCR_VPPTI        0x00000002
 #define VTCR_VGTI        0x00000001
 
 #define CR                0x00
 #define CFG                0x04
 #define MEAR                0x08
 #define PTSCR                0x0c
 #define        ISR                0x10
 #define        IMR                0x14
 #define        IER                0x18
 #define        IHR                0x1c
 #define TXDP                0x20
 #define TXDP_HI                0x24
 #define TXCFG                0x28
 #define GPIOR                0x2c
 #define RXDP                0x30
 #define RXDP_HI                0x34
 #define RXCFG                0x38
 #define PQCR                0x3c
 #define WCSR                0x40
 #define PCR                0x44
 #define RFCR                0x48
 #define RFDR                0x4c
 
 #define SRR                0x58
 
 #define VRCR                0xbc
 #define VTCR                0xc0
 #define VDR                0xc4
 #define CCSR                0xcc
 
 #define TBICR                0xe0
 #define TBISR                0xe4
 #define TANAR                0xe8
 #define TANLPAR                0xec
 #define TANER                0xf0
 #define TESR                0xf4
 
 #define TBICR_MR_AN_ENABLE        0x00001000
 #define TBICR_MR_RESTART_AN        0x00000200
 
 #define TBISR_MR_LINK_STATUS        0x00000020
 #define TBISR_MR_AN_COMPLETE        0x00000004
 
 #define TANAR_PS2                 0x00000100
 #define TANAR_PS1                 0x00000080
 #define TANAR_HALF_DUP                 0x00000040
 #define TANAR_FULL_DUP                 0x00000020
 
 #define GPIOR_GP5_OE                0x00000200
 #define GPIOR_GP4_OE                0x00000100
 #define GPIOR_GP3_OE                0x00000080
 #define GPIOR_GP2_OE                0x00000040
 #define GPIOR_GP1_OE                0x00000020
 #define GPIOR_GP3_OUT                0x00000004
 #define GPIOR_GP1_OUT                0x00000001
 
 #define LINK_AUTONEGOTIATE        0x01
 #define LINK_DOWN                0x02
 #define LINK_UP                        0x04
 
 #define HW_ADDR_LEN        sizeof(dma_addr_t)
 #define desc_addr_set(desc, addr)                                \
         do {                                                        \
                 ((desc)[0] = cpu_to_le32(addr));                \
                 if (HW_ADDR_LEN == 8)                                 \
                         (desc)[1] = cpu_to_le32(((u64)addr) >> 32);        \
         } while(0)
 #define desc_addr_get(desc)                                        \
         (le32_to_cpu((desc)[0]) | \
         (HW_ADDR_LEN == 8 ? ((dma_addr_t)le32_to_cpu((desc)[1]))<<32 : 0))
 
 #define DESC_LINK                0
 #define DESC_BUFPTR                (DESC_LINK + HW_ADDR_LEN/4)
 #define DESC_CMDSTS                (DESC_BUFPTR + HW_ADDR_LEN/4)
 #define DESC_EXTSTS                (DESC_CMDSTS + 4/4)
 
 #define CMDSTS_OWN        0x80000000
 #define CMDSTS_MORE        0x40000000
 #define CMDSTS_INTR        0x20000000
 #define CMDSTS_ERR        0x10000000
 #define CMDSTS_OK        0x08000000
 #define CMDSTS_RUNT        0x00200000
 #define CMDSTS_LEN_MASK        0x0000ffff
 
 #define CMDSTS_DEST_MASK        0x01800000
 #define CMDSTS_DEST_SELF        0x00800000
 #define CMDSTS_DEST_MULTI        0x01000000
 
 #define DESC_SIZE        8                /* Should be cache line sized */
 
 struct rx_info {
         spinlock_t        lock;
         int                up;
         long                idle;
 
         struct sk_buff        *skbs[NR_RX_DESC];
 
         __le32                *next_rx_desc;
         u16                next_rx, next_empty;
 
         __le32                *descs;
         dma_addr_t        phy_descs;
 };
 
 
 struct ns83820 {
         struct net_device_stats        stats;
         u8                        __iomem *base;
 
         struct pci_dev                *pci_dev;
         struct net_device        *ndev;
 
 #ifdef NS83820_VLAN_ACCEL_SUPPORT
         struct vlan_group        *vlgrp;
 #endif
 
         struct rx_info                rx_info;
         struct tasklet_struct        rx_tasklet;
 
         unsigned                ihr;
         struct work_struct        tq_refill;
 
         /* protects everything below.  irqsave when using. */
         spinlock_t                misc_lock;
 
         u32                        CFG_cache;
 
         u32                        MEAR_cache;
         u32                        IMR_cache;
 
         unsigned                linkstate;
 
         spinlock_t        tx_lock;
 
         u16                tx_done_idx;
         u16                tx_idx;
         volatile u16        tx_free_idx;        /* idx of free desc chain */
         u16                tx_intr_idx;
 
         atomic_t        nr_tx_skbs;
         struct sk_buff        *tx_skbs[NR_TX_DESC];
 
         char                pad[16] __attribute__((aligned(16)));
         __le32                *tx_descs;
         dma_addr_t        tx_phy_descs;
 
         struct timer_list        tx_watchdog;
 };
 
 static inline struct ns83820 *PRIV(struct net_device *dev)
 {
         return netdev_priv(dev);
 }
 
 #define __kick_rx(dev)        writel(CR_RXE, dev->base + CR)
 
 static inline void kick_rx(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         dprintk("kick_rx: maybe kicking\n");
         if (test_and_clear_bit(0, &dev->rx_info.idle)) {
                 dprintk("actually kicking\n");
                 writel(dev->rx_info.phy_descs +
                         (4 * DESC_SIZE * dev->rx_info.next_rx),
                        dev->base + RXDP);
                 if (dev->rx_info.next_rx == dev->rx_info.next_empty)
                         printk(KERN_DEBUG "%s: uh-oh: next_rx == next_empty???\n",
                                 ndev->name);
                 __kick_rx(dev);
         }
 }
 
 //free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC
 #define start_tx_okay(dev)        \
         (((NR_TX_DESC-2 + dev->tx_done_idx - dev->tx_free_idx) % NR_TX_DESC) > MIN_TX_DESC_FREE)
 
 
 #ifdef NS83820_VLAN_ACCEL_SUPPORT
 static void ns83820_vlan_rx_register(struct net_device *ndev, struct vlan_group *grp)
 {
         struct ns83820 *dev = PRIV(ndev);
 
         spin_lock_irq(&dev->misc_lock);
         spin_lock(&dev->tx_lock);
 
         dev->vlgrp = grp;
 
         spin_unlock(&dev->tx_lock);
         spin_unlock_irq(&dev->misc_lock);
 }
 #endif
 
 /* Packet Receiver
  *
  * The hardware supports linked lists of receive descriptors for
  * which ownership is transfered back and forth by means of an
  * ownership bit.  While the hardware does support the use of a
  * ring for receive descriptors, we only make use of a chain in
  * an attempt to reduce bus traffic under heavy load scenarios.
  * This will also make bugs a bit more obvious.  The current code
  * only makes use of a single rx chain; I hope to implement
  * priority based rx for version 1.0.  Goal: even under overload
  * conditions, still route realtime traffic with as low jitter as
  * possible.
  */
 static inline void build_rx_desc(struct ns83820 *dev, __le32 *desc, dma_addr_t link, dma_addr_t buf, u32 cmdsts, u32 extsts)
 {
         desc_addr_set(desc + DESC_LINK, link);
         desc_addr_set(desc + DESC_BUFPTR, buf);
         desc[DESC_EXTSTS] = cpu_to_le32(extsts);
         mb();
         desc[DESC_CMDSTS] = cpu_to_le32(cmdsts);
 }
 
 #define nr_rx_empty(dev) ((NR_RX_DESC-2 + dev->rx_info.next_rx - dev->rx_info.next_empty) % NR_RX_DESC)
 static inline int ns83820_add_rx_skb(struct ns83820 *dev, struct sk_buff *skb)
 {
         unsigned next_empty;
         u32 cmdsts;
         __le32 *sg;
         dma_addr_t buf;
 
         next_empty = dev->rx_info.next_empty;
 
         /* don't overrun last rx marker */
         if (unlikely(nr_rx_empty(dev) <= 2)) {
                 kfree_skb(skb);
                 return 1;
         }
 
 #if 0
         dprintk("next_empty[%d] nr_used[%d] next_rx[%d]\n",
                 dev->rx_info.next_empty,
                 dev->rx_info.nr_used,
                 dev->rx_info.next_rx
                 );
 #endif
 
         sg = dev->rx_info.descs + (next_empty * DESC_SIZE);
         BUG_ON(NULL != dev->rx_info.skbs[next_empty]);
         dev->rx_info.skbs[next_empty] = skb;
 
         dev->rx_info.next_empty = (next_empty + 1) % NR_RX_DESC;
         cmdsts = REAL_RX_BUF_SIZE | CMDSTS_INTR;
         buf = pci_map_single(dev->pci_dev, skb->data,
                              REAL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
         build_rx_desc(dev, sg, 0, buf, cmdsts, 0);
         /* update link of previous rx */
         if (likely(next_empty != dev->rx_info.next_rx))
                 dev->rx_info.descs[((NR_RX_DESC + next_empty - 1) % NR_RX_DESC) * DESC_SIZE] = cpu_to_le32(dev->rx_info.phy_descs + (next_empty * DESC_SIZE * 4));
 
         return 0;
 }
 
 static inline int rx_refill(struct net_device *ndev, gfp_t gfp)
 {
         struct ns83820 *dev = PRIV(ndev);
         unsigned i;
         unsigned long flags = 0;
 
         if (unlikely(nr_rx_empty(dev) <= 2))
                 return 0;
 
         dprintk("rx_refill(%p)\n", ndev);
         if (gfp == GFP_ATOMIC)
                 spin_lock_irqsave(&dev->rx_info.lock, flags);
         for (i=0; i<NR_RX_DESC; i++) {
                 struct sk_buff *skb;
                 long res;
 
                 /* extra 16 bytes for alignment */
                 skb = __netdev_alloc_skb(ndev, REAL_RX_BUF_SIZE+16, gfp);
                 if (unlikely(!skb))
                         break;
 
                 skb_reserve(skb, skb->data - PTR_ALIGN(skb->data, 16));
                 if (gfp != GFP_ATOMIC)
                         spin_lock_irqsave(&dev->rx_info.lock, flags);
                 res = ns83820_add_rx_skb(dev, skb);
                 if (gfp != GFP_ATOMIC)
                         spin_unlock_irqrestore(&dev->rx_info.lock, flags);
                 if (res) {
                         i = 1;
                         break;
                 }
         }
         if (gfp == GFP_ATOMIC)
                 spin_unlock_irqrestore(&dev->rx_info.lock, flags);
 
         return i ? 0 : -ENOMEM;
 }
 
 static void rx_refill_atomic(struct net_device *ndev)
 {
         rx_refill(ndev, GFP_ATOMIC);
 }
 
 /* REFILL */
 static inline void queue_refill(struct work_struct *work)
 {
         struct ns83820 *dev = container_of(work, struct ns83820, tq_refill);
         struct net_device *ndev = dev->ndev;
 
         rx_refill(ndev, GFP_KERNEL);
         if (dev->rx_info.up)
                 kick_rx(ndev);
 }
 
 static inline void clear_rx_desc(struct ns83820 *dev, unsigned i)
 {
         build_rx_desc(dev, dev->rx_info.descs + (DESC_SIZE * i), 0, 0, CMDSTS_OWN, 0);
 }
 
 static void phy_intr(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         static const char *speeds[] = { "10", "100", "1000", "1000(?)", "1000F" };
         u32 cfg, new_cfg;
         u32 tbisr, tanar, tanlpar;
         int speed, fullduplex, newlinkstate;
 
         cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
 
         if (dev->CFG_cache & CFG_TBI_EN) {
                 /* we have an optical transceiver */
                 tbisr = readl(dev->base + TBISR);
                 tanar = readl(dev->base + TANAR);
                 tanlpar = readl(dev->base + TANLPAR);
                 dprintk("phy_intr: tbisr=%08x, tanar=%08x, tanlpar=%08x\n",
                         tbisr, tanar, tanlpar);
 
                 if ( (fullduplex = (tanlpar & TANAR_FULL_DUP)
                       && (tanar & TANAR_FULL_DUP)) ) {
 
                         /* both of us are full duplex */
                         writel(readl(dev->base + TXCFG)
                                | TXCFG_CSI | TXCFG_HBI | TXCFG_ATP,
                                dev->base + TXCFG);
                         writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
                                dev->base + RXCFG);
                         /* Light up full duplex LED */
                         writel(readl(dev->base + GPIOR) | GPIOR_GP1_OUT,
                                dev->base + GPIOR);
 
                 } else if(((tanlpar & TANAR_HALF_DUP)
                            && (tanar & TANAR_HALF_DUP))
                         || ((tanlpar & TANAR_FULL_DUP)
                             && (tanar & TANAR_HALF_DUP))
                         || ((tanlpar & TANAR_HALF_DUP)
                             && (tanar & TANAR_FULL_DUP))) {
 
                         /* one or both of us are half duplex */
                         writel((readl(dev->base + TXCFG)
                                 & ~(TXCFG_CSI | TXCFG_HBI)) | TXCFG_ATP,
                                dev->base + TXCFG);
                         writel(readl(dev->base + RXCFG) & ~RXCFG_RX_FD,
                                dev->base + RXCFG);
                         /* Turn off full duplex LED */
                         writel(readl(dev->base + GPIOR) & ~GPIOR_GP1_OUT,
                                dev->base + GPIOR);
                 }
 
                 speed = 4; /* 1000F */
 
         } else {
                 /* we have a copper transceiver */
                 new_cfg = dev->CFG_cache & ~(CFG_SB | CFG_MODE_1000 | CFG_SPDSTS);
 
                 if (cfg & CFG_SPDSTS1)
                         new_cfg |= CFG_MODE_1000;
                 else
                         new_cfg &= ~CFG_MODE_1000;
 
                 speed = ((cfg / CFG_SPDSTS0) & 3);
                 fullduplex = (cfg & CFG_DUPSTS);
 
                 if (fullduplex) {
                         new_cfg |= CFG_SB;
                         writel(readl(dev->base + TXCFG)
                                         | TXCFG_CSI | TXCFG_HBI,
                                dev->base + TXCFG);
                         writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
                                dev->base + RXCFG);
                 } else {
                         writel(readl(dev->base + TXCFG)
                                         & ~(TXCFG_CSI | TXCFG_HBI),
                                dev->base + TXCFG);
                         writel(readl(dev->base + RXCFG) & ~(RXCFG_RX_FD),
                                dev->base + RXCFG);
                 }
 
                 if ((cfg & CFG_LNKSTS) &&
                     ((new_cfg ^ dev->CFG_cache) != 0)) {
                         writel(new_cfg, dev->base + CFG);
                         dev->CFG_cache = new_cfg;
                 }
 
                 dev->CFG_cache &= ~CFG_SPDSTS;
                 dev->CFG_cache |= cfg & CFG_SPDSTS;
         }
 
         newlinkstate = (cfg & CFG_LNKSTS) ? LINK_UP : LINK_DOWN;
 
         if (newlinkstate & LINK_UP
             && dev->linkstate != newlinkstate) {
                 netif_start_queue(ndev);
                 netif_wake_queue(ndev);
                 printk(KERN_INFO "%s: link now %s mbps, %s duplex and up.\n",
                         ndev->name,
                         speeds[speed],
                         fullduplex ? "full" : "half");
         } else if (newlinkstate & LINK_DOWN
                    && dev->linkstate != newlinkstate) {
                 netif_stop_queue(ndev);
                 printk(KERN_INFO "%s: link now down.\n", ndev->name);
         }
 
         dev->linkstate = newlinkstate;
 }
 
 static int ns83820_setup_rx(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         unsigned i;
         int ret;
 
         dprintk("ns83820_setup_rx(%p)\n", ndev);
 
         dev->rx_info.idle = 1;
         dev->rx_info.next_rx = 0;
         dev->rx_info.next_rx_desc = dev->rx_info.descs;
         dev->rx_info.next_empty = 0;
 
         for (i=0; i<NR_RX_DESC; i++)
                 clear_rx_desc(dev, i);
 
         writel(0, dev->base + RXDP_HI);
         writel(dev->rx_info.phy_descs, dev->base + RXDP);
 
         ret = rx_refill(ndev, GFP_KERNEL);
         if (!ret) {
                 dprintk("starting receiver\n");
                 /* prevent the interrupt handler from stomping on us */
                 spin_lock_irq(&dev->rx_info.lock);
 
                 writel(0x0001, dev->base + CCSR);
                 writel(0, dev->base + RFCR);
                 writel(0x7fc00000, dev->base + RFCR);
                 writel(0xffc00000, dev->base + RFCR);
 
                 dev->rx_info.up = 1;
 
                 phy_intr(ndev);
 
                 /* Okay, let it rip */
                 spin_lock_irq(&dev->misc_lock);
                 dev->IMR_cache |= ISR_PHY;
                 dev->IMR_cache |= ISR_RXRCMP;
                 //dev->IMR_cache |= ISR_RXERR;
                 //dev->IMR_cache |= ISR_RXOK;
                 dev->IMR_cache |= ISR_RXORN;
                 dev->IMR_cache |= ISR_RXSOVR;
                 dev->IMR_cache |= ISR_RXDESC;
                 dev->IMR_cache |= ISR_RXIDLE;
                 dev->IMR_cache |= ISR_TXDESC;
                 dev->IMR_cache |= ISR_TXIDLE;
 
                 writel(dev->IMR_cache, dev->base + IMR);
                 writel(1, dev->base + IER);
                 spin_unlock(&dev->misc_lock);
 
                 kick_rx(ndev);
 
                 spin_unlock_irq(&dev->rx_info.lock);
         }
         return ret;
 }
 
 static void ns83820_cleanup_rx(struct ns83820 *dev)
 {
         unsigned i;
         unsigned long flags;
 
         dprintk("ns83820_cleanup_rx(%p)\n", dev);
 
         /* disable receive interrupts */
         spin_lock_irqsave(&dev->misc_lock, flags);
         dev->IMR_cache &= ~(ISR_RXOK | ISR_RXDESC | ISR_RXERR | ISR_RXEARLY | ISR_RXIDLE);
         writel(dev->IMR_cache, dev->base + IMR);
         spin_unlock_irqrestore(&dev->misc_lock, flags);
 
         /* synchronize with the interrupt handler and kill it */
         dev->rx_info.up = 0;
         synchronize_irq(dev->pci_dev->irq);
 
         /* touch the pci bus... */
         readl(dev->base + IMR);
 
         /* assumes the transmitter is already disabled and reset */
         writel(0, dev->base + RXDP_HI);
         writel(0, dev->base + RXDP);
 
         for (i=0; i<NR_RX_DESC; i++) {
                 struct sk_buff *skb = dev->rx_info.skbs[i];
                 dev->rx_info.skbs[i] = NULL;
                 clear_rx_desc(dev, i);
                 if (skb)
                         kfree_skb(skb);
         }
 }
 
 static void ns83820_rx_kick(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         /*if (nr_rx_empty(dev) >= NR_RX_DESC/4)*/ {
                 if (dev->rx_info.up) {
                         rx_refill_atomic(ndev);
                         kick_rx(ndev);
                 }
         }
 
         if (dev->rx_info.up && nr_rx_empty(dev) > NR_RX_DESC*3/4)
                 schedule_work(&dev->tq_refill);
         else
                 kick_rx(ndev);
         if (dev->rx_info.idle)
                 printk(KERN_DEBUG "%s: BAD\n", ndev->name);
 }
 
 /* rx_irq
  *
  */
 static void rx_irq(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         struct rx_info *info = &dev->rx_info;
         unsigned next_rx;
         int rx_rc, len;
         u32 cmdsts;
         __le32 *desc;
         unsigned long flags;
         int nr = 0;
 
         dprintk("rx_irq(%p)\n", ndev);
         dprintk("rxdp: %08x, descs: %08lx next_rx[%d]: %p next_empty[%d]: %p\n",
                 readl(dev->base + RXDP),
                 (long)(dev->rx_info.phy_descs),
                 (int)dev->rx_info.next_rx,
                 (dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_rx)),
                 (int)dev->rx_info.next_empty,
                 (dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_empty))
                 );
 
         spin_lock_irqsave(&info->lock, flags);
         if (!info->up)
                 goto out;
 
         dprintk("walking descs\n");
         next_rx = info->next_rx;
         desc = info->next_rx_desc;
         while ((CMDSTS_OWN & (cmdsts = le32_to_cpu(desc[DESC_CMDSTS]))) &&
                (cmdsts != CMDSTS_OWN)) {
                 struct sk_buff *skb;
                 u32 extsts = le32_to_cpu(desc[DESC_EXTSTS]);
                 dma_addr_t bufptr = desc_addr_get(desc + DESC_BUFPTR);
 
                 dprintk("cmdsts: %08x\n", cmdsts);
                 dprintk("link: %08x\n", cpu_to_le32(desc[DESC_LINK]));
                 dprintk("extsts: %08x\n", extsts);
 
                 skb = info->skbs[next_rx];
                 info->skbs[next_rx] = NULL;
                 info->next_rx = (next_rx + 1) % NR_RX_DESC;
 
                 mb();
                 clear_rx_desc(dev, next_rx);
 
                 pci_unmap_single(dev->pci_dev, bufptr,
                                  RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
                 len = cmdsts & CMDSTS_LEN_MASK;
 #ifdef NS83820_VLAN_ACCEL_SUPPORT
                 /* NH: As was mentioned below, this chip is kinda
                  * brain dead about vlan tag stripping.  Frames
                  * that are 64 bytes with a vlan header appended
                  * like arp frames, or pings, are flagged as Runts
                  * when the tag is stripped and hardware.  This
                  * also means that the OK bit in the descriptor
                  * is cleared when the frame comes in so we have
                  * to do a specific length check here to make sure
                  * the frame would have been ok, had we not stripped
                  * the tag.
                  */
                 if (likely((CMDSTS_OK & cmdsts) ||
                         ((cmdsts & CMDSTS_RUNT) && len >= 56))) {
 #else
                 if (likely(CMDSTS_OK & cmdsts)) {
 #endif
                         skb_put(skb, len);
                         if (unlikely(!skb))
                                 goto netdev_mangle_me_harder_failed;
                         if (cmdsts & CMDSTS_DEST_MULTI)
                                 dev->stats.multicast ++;
                         dev->stats.rx_packets ++;
                         dev->stats.rx_bytes += len;
                         if ((extsts & 0x002a0000) && !(extsts & 0x00540000)) {
                                 skb->ip_summed = CHECKSUM_UNNECESSARY;
                         } else {
                                 skb->ip_summed = CHECKSUM_NONE;
                         }
                         skb->protocol = eth_type_trans(skb, ndev);
 #ifdef NS83820_VLAN_ACCEL_SUPPORT
                         if(extsts & EXTSTS_VPKT) {
                                 unsigned short tag;
                                 tag = ntohs(extsts & EXTSTS_VTG_MASK);
                                 rx_rc = vlan_hwaccel_rx(skb,dev->vlgrp,tag);
                         } else {
                                 rx_rc = netif_rx(skb);
                         }
 #else
                         rx_rc = netif_rx(skb);
 #endif
                         if (NET_RX_DROP == rx_rc) {
 netdev_mangle_me_harder_failed:
                                 dev->stats.rx_dropped ++;
                         }
                 } else {
                         kfree_skb(skb);
                 }
 
                 nr++;
                 next_rx = info->next_rx;
                 desc = info->descs + (DESC_SIZE * next_rx);
         }
         info->next_rx = next_rx;
         info->next_rx_desc = info->descs + (DESC_SIZE * next_rx);
 
 out:
         if (0 && !nr) {
                 Dprintk("dazed: cmdsts_f: %08x\n", cmdsts);
         }
 
         spin_unlock_irqrestore(&info->lock, flags);
 }
 
 static void rx_action(unsigned long _dev)
 {
         struct net_device *ndev = (void *)_dev;
         struct ns83820 *dev = PRIV(ndev);
         rx_irq(ndev);
         writel(ihr, dev->base + IHR);
 
         spin_lock_irq(&dev->misc_lock);
         dev->IMR_cache |= ISR_RXDESC;
         writel(dev->IMR_cache, dev->base + IMR);
         spin_unlock_irq(&dev->misc_lock);
 
         rx_irq(ndev);
         ns83820_rx_kick(ndev);
 }
 
 /* Packet Transmit code
  */
 static inline void kick_tx(struct ns83820 *dev)
 {
         dprintk("kick_tx(%p): tx_idx=%d free_idx=%d\n",
                 dev, dev->tx_idx, dev->tx_free_idx);
         writel(CR_TXE, dev->base + CR);
 }
 
 /* No spinlock needed on the transmit irq path as the interrupt handler is
  * serialized.
  */
 static void do_tx_done(struct net_device *ndev)
 {
         struct ns83820 *dev = PRIV(ndev);
         u32 cmdsts, tx_done_idx;
         __le32 *desc;
 
         dprintk("do_tx_done(%p)\n", ndev);
         tx_done_idx = dev->tx_done_idx;
         desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);

        dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
                tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));
        while ((tx_done_idx != dev->tx_free_idx) &&
               !(CMDSTS_OWN & (cmdsts = le32_to_cpu(desc[DESC_CMDSTS]))) ) {
                struct sk_buff *skb;
                unsigned len;
                dma_addr_t addr;

                if (cmdsts & CMDSTS_ERR)
                        dev->stats.tx_errors ++;
                if (cmdsts & CMDSTS_OK)
                        dev->stats.tx_packets ++;
                if (cmdsts & CMDSTS_OK)
                        dev->stats.tx_bytes += cmdsts & 0xffff;

                dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
                        tx_done_idx, dev->tx_free_idx, cmdsts);
                skb = dev->tx_skbs[tx_done_idx];
                dev->tx_skbs[tx_done_idx] = NULL;
                dprintk("done(%p)\n", skb);

                len = cmdsts & CMDSTS_LEN_MASK;
                addr = desc_addr_get(desc + DESC_BUFPTR);
                if (skb) {
                        pci_unmap_single(dev->pci_dev,
                                        addr,
                                        len,
                                        PCI_DMA_TODEVICE);
                        dev_kfree_skb_irq(skb);
                        atomic_dec(&dev->nr_tx_skbs);
                } else
                        pci_unmap_page(dev->pci_dev,
                                        addr,
                                        len,
                                        PCI_DMA_TODEVICE);

                tx_done_idx = (tx_done_idx + 1) % NR_TX_DESC;
                dev->tx_done_idx = tx_done_idx;
                desc[DESC_CMDSTS] = cpu_to_le32(0);
                mb();
                desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
        }

        /* Allow network stack to resume queueing packets after we've
         * finished transmitting at least 1/4 of the packets in the queue.
         */
        if (netif_queue_stopped(ndev) && start_tx_okay(dev)) {
                dprintk("start_queue(%p)\n", ndev);
                netif_start_queue(ndev);
                netif_wake_queue(ndev);
        }
}

static void ns83820_cleanup_tx(struct ns83820 *dev)
{
        unsigned i;

        for (i=0; i<NR_TX_DESC; i++) {
                struct sk_buff *skb = dev->tx_skbs[i];
                dev->tx_skbs[i] = NULL;
                if (skb) {
                        __le32 *desc = dev->tx_descs + (i * DESC_SIZE);
                        pci_unmap_single(dev->pci_dev,
                                        desc_addr_get(desc + DESC_BUFPTR),
                                        le32_to_cpu(desc[DESC_CMDSTS]) & CMDSTS_LEN_MASK,
                                        PCI_DMA_TODEVICE);
                        dev_kfree_skb_irq(skb);
                        atomic_dec(&dev->nr_tx_skbs);
                }
        }

        memset(dev->tx_descs, 0, NR_TX_DESC * DESC_SIZE * 4);
}

/* transmit routine.  This code relies on the network layer serializing
 * its calls in, but will run happily in parallel with the interrupt
 * handler.  This code currently has provisions for fragmenting tx buffers
 * while trying to track down a bug in either the zero copy code or
 * the tx fifo (hence the MAX_FRAG_LEN).
 */
static int ns83820_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        u32 free_idx, cmdsts, extsts;
        int nr_free, nr_frags;
        unsigned tx_done_idx, last_idx;
        dma_addr_t buf;
        unsigned len;
        skb_frag_t *frag;
        int stopped = 0;
        int do_intr = 0;
        volatile __le32 *first_desc;

        dprintk("ns83820_hard_start_xmit\n");

        nr_frags =  skb_shinfo(skb)->nr_frags;
again:
        if (unlikely(dev->CFG_cache & CFG_LNKSTS)) {
                netif_stop_queue(ndev);
                if (unlikely(dev->CFG_cache & CFG_LNKSTS))
                        return 1;
                netif_start_queue(ndev);
        }

        last_idx = free_idx = dev->tx_free_idx;
        tx_done_idx = dev->tx_done_idx;
        nr_free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC;
        nr_free -= 1;
        if (nr_free <= nr_frags) {
                dprintk("stop_queue - not enough(%p)\n", ndev);
                netif_stop_queue(ndev);

                /* Check again: we may have raced with a tx done irq */
                if (dev->tx_done_idx != tx_done_idx) {
                        dprintk("restart queue(%p)\n", ndev);
                        netif_start_queue(ndev);
                        goto again;
                }
                return 1;
        }

        if (free_idx == dev->tx_intr_idx) {
                do_intr = 1;
                dev->tx_intr_idx = (dev->tx_intr_idx + NR_TX_DESC/4) % NR_TX_DESC;
        }

        nr_free -= nr_frags;
        if (nr_free < MIN_TX_DESC_FREE) {
                dprintk("stop_queue - last entry(%p)\n", ndev);
                netif_stop_queue(ndev);
                stopped = 1;
        }

        frag = skb_shinfo(skb)->frags;
        if (!nr_frags)
                frag = NULL;
        extsts = 0;
        if (skb->ip_summed == CHECKSUM_PARTIAL) {
                extsts |= EXTSTS_IPPKT;
                if (IPPROTO_TCP == ip_hdr(skb)->protocol)
                        extsts |= EXTSTS_TCPPKT;
                else if (IPPROTO_UDP == ip_hdr(skb)->protocol)
                        extsts |= EXTSTS_UDPPKT;
        }

#ifdef NS83820_VLAN_ACCEL_SUPPORT
        if(vlan_tx_tag_present(skb)) {
                /* fetch the vlan tag info out of the
                 * ancilliary data if the vlan code
                 * is using hw vlan acceleration
                 */
                short tag = vlan_tx_tag_get(skb);
                extsts |= (EXTSTS_VPKT | htons(tag));
        }
#endif

        len = skb->len;
        if (nr_frags)
                len -= skb->data_len;
        buf = pci_map_single(dev->pci_dev, skb->data, len, PCI_DMA_TODEVICE);

        first_desc = dev->tx_descs + (free_idx * DESC_SIZE);

        for (;;) {
                volatile __le32 *desc = dev->tx_descs + (free_idx * DESC_SIZE);

                dprintk("frag[%3u]: %4u @ 0x%08Lx\n", free_idx, len,
                        (unsigned long long)buf);
                last_idx = free_idx;
                free_idx = (free_idx + 1) % NR_TX_DESC;
                desc[DESC_LINK] = cpu_to_le32(dev->tx_phy_descs + (free_idx * DESC_SIZE * 4));
                desc_addr_set(desc + DESC_BUFPTR, buf);
                desc[DESC_EXTSTS] = cpu_to_le32(extsts);

                cmdsts = ((nr_frags) ? CMDSTS_MORE : do_intr ? CMDSTS_INTR : 0);
                cmdsts |= (desc == first_desc) ? 0 : CMDSTS_OWN;
                cmdsts |= len;
                desc[DESC_CMDSTS] = cpu_to_le32(cmdsts);

                if (!nr_frags)
                        break;

                buf = pci_map_page(dev->pci_dev, frag->page,
                                   frag->page_offset,
                                   frag->size, PCI_DMA_TODEVICE);
                dprintk("frag: buf=%08Lx  page=%08lx offset=%08lx\n",
                        (long long)buf, (long) page_to_pfn(frag->page),
                        frag->page_offset);
                len = frag->size;
                frag++;
                nr_frags--;
        }
        dprintk("done pkt\n");

        spin_lock_irq(&dev->tx_lock);
        dev->tx_skbs[last_idx] = skb;
        first_desc[DESC_CMDSTS] |= cpu_to_le32(CMDSTS_OWN);
        dev->tx_free_idx = free_idx;
        atomic_inc(&dev->nr_tx_skbs);
        spin_unlock_irq(&dev->tx_lock);

        kick_tx(dev);

        /* Check again: we may have raced with a tx done irq */
        if (stopped && (dev->tx_done_idx != tx_done_idx) && start_tx_okay(dev))
                netif_start_queue(ndev);

        /* set the transmit start time to catch transmit timeouts */
        ndev->trans_start = jiffies;
        return 0;
}

static void ns83820_update_stats(struct ns83820 *dev)
{
        u8 __iomem *base = dev->base;

        /* the DP83820 will freeze counters, so we need to read all of them */
        dev->stats.rx_errors                += readl(base + 0x60) & 0xffff;
        dev->stats.rx_crc_errors        += readl(base + 0x64) & 0xffff;
        dev->stats.rx_missed_errors        += readl(base + 0x68) & 0xffff;
        dev->stats.rx_frame_errors        += readl(base + 0x6c) & 0xffff;
        /*dev->stats.rx_symbol_errors +=*/ readl(base + 0x70);
        dev->stats.rx_length_errors        += readl(base + 0x74) & 0xffff;
        dev->stats.rx_length_errors        += readl(base + 0x78) & 0xffff;
        /*dev->stats.rx_badopcode_errors += */ readl(base + 0x7c);
        /*dev->stats.rx_pause_count += */  readl(base + 0x80);
        /*dev->stats.tx_pause_count += */  readl(base + 0x84);
        dev->stats.tx_carrier_errors        += readl(base + 0x88) & 0xff;
}

static struct net_device_stats *ns83820_get_stats(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);

        /* somewhat overkill */
        spin_lock_irq(&dev->misc_lock);
        ns83820_update_stats(dev);
        spin_unlock_irq(&dev->misc_lock);

        return &dev->stats;
}

/* Let ethtool retrieve info */
static int ns83820_get_settings(struct net_device *ndev,
                                struct ethtool_cmd *cmd)
{
        struct ns83820 *dev = PRIV(ndev);
        u32 cfg, tanar, tbicr;
        int have_optical = 0;
        int fullduplex   = 0;

        /*
         * Here's the list of available ethtool commands from other drivers:
         *        cmd->advertising =
         *        cmd->speed =
         *        cmd->duplex =
         *        cmd->port = 0;
         *        cmd->phy_address =
         *        cmd->transceiver = 0;
         *        cmd->autoneg =
         *        cmd->maxtxpkt = 0;
         *        cmd->maxrxpkt = 0;
         */

        /* read current configuration */
        cfg   = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
        tanar = readl(dev->base + TANAR);
        tbicr = readl(dev->base + TBICR);

        if (dev->CFG_cache & CFG_TBI_EN) {
                /* we have an optical interface */
                have_optical = 1;
                fullduplex = (cfg & CFG_DUPSTS) ? 1 : 0;

        } else {
                /* We have copper */
                fullduplex = (cfg & CFG_DUPSTS) ? 1 : 0;
        }

        cmd->supported = SUPPORTED_Autoneg;

        /* we have optical interface */
        if (dev->CFG_cache & CFG_TBI_EN) {
                cmd->supported |= SUPPORTED_1000baseT_Half |
                                        SUPPORTED_1000baseT_Full |
                                        SUPPORTED_FIBRE;
                cmd->port       = PORT_FIBRE;
        } /* TODO: else copper related  support */

        cmd->duplex = fullduplex ? DUPLEX_FULL : DUPLEX_HALF;
        switch (cfg / CFG_SPDSTS0 & 3) {
        case 2:
                cmd->speed = SPEED_1000;
                break;
        case 1:
                cmd->speed = SPEED_100;
                break;
        default:
                cmd->speed = SPEED_10;
                break;
        }
        cmd->autoneg = (tbicr & TBICR_MR_AN_ENABLE) ? 1: 0;
        return 0;
}

/* Let ethool change settings*/
static int ns83820_set_settings(struct net_device *ndev,
                                struct ethtool_cmd *cmd)
{
        struct ns83820 *dev = PRIV(ndev);
        u32 cfg, tanar;
        int have_optical = 0;
        int fullduplex   = 0;

        /* read current configuration */
        cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
        tanar = readl(dev->base + TANAR);

        if (dev->CFG_cache & CFG_TBI_EN) {
                /* we have optical */
                have_optical = 1;
                fullduplex   = (tanar & TANAR_FULL_DUP);

        } else {
                /* we have copper */
                fullduplex = cfg & CFG_DUPSTS;
        }

        spin_lock_irq(&dev->misc_lock);
        spin_lock(&dev->tx_lock);

        /* Set duplex */
        if (cmd->duplex != fullduplex) {
                if (have_optical) {
                        /*set full duplex*/
                        if (cmd->duplex == DUPLEX_FULL) {
                                /* force full duplex */
                                writel(readl(dev->base + TXCFG)
                                        | TXCFG_CSI | TXCFG_HBI | TXCFG_ATP,
                                        dev->base + TXCFG);
                                writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
                                        dev->base + RXCFG);
                                /* Light up full duplex LED */
                                writel(readl(dev->base + GPIOR) | GPIOR_GP1_OUT,
                                        dev->base + GPIOR);
                        } else {
                                /*TODO: set half duplex */
                        }

                } else {
                        /*we have copper*/
                        /* TODO: Set duplex for copper cards */
                }
                printk(KERN_INFO "%s: Duplex set via ethtool\n",
                ndev->name);
        }

        /* Set autonegotiation */
        if (1) {
                if (cmd->autoneg == AUTONEG_ENABLE) {
                        /* restart auto negotiation */
                        writel(TBICR_MR_AN_ENABLE | TBICR_MR_RESTART_AN,
                                dev->base + TBICR);
                        writel(TBICR_MR_AN_ENABLE, dev->base + TBICR);
                                dev->linkstate = LINK_AUTONEGOTIATE;

                        printk(KERN_INFO "%s: autoneg enabled via ethtool\n",
                                ndev->name);
                } else {
                        /* disable auto negotiation */
                        writel(0x00000000, dev->base + TBICR);
                }

                printk(KERN_INFO "%s: autoneg %s via ethtool\n", ndev->name,
                                cmd->autoneg ? "ENABLED" : "DISABLED");
        }

        phy_intr(ndev);
        spin_unlock(&dev->tx_lock);
        spin_unlock_irq(&dev->misc_lock);

        return 0;
}
/* end ethtool get/set support -df */

static void ns83820_get_drvinfo(struct net_device *ndev, struct ethtool_drvinfo *info)
{
        struct ns83820 *dev = PRIV(ndev);
        strcpy(info->driver, "ns83820");
        strcpy(info->version, VERSION);
        strcpy(info->bus_info, pci_name(dev->pci_dev));
}

static u32 ns83820_get_link(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        u32 cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
        return cfg & CFG_LNKSTS ? 1 : 0;
}

static const struct ethtool_ops ops = {
        .get_settings    = ns83820_get_settings,
        .set_settings    = ns83820_set_settings,
        .get_drvinfo     = ns83820_get_drvinfo,
        .get_link        = ns83820_get_link
};

/* this function is called in irq context from the ISR */
static void ns83820_mib_isr(struct ns83820 *dev)
{
        unsigned long flags;
        spin_lock_irqsave(&dev->misc_lock, flags);
        ns83820_update_stats(dev);
        spin_unlock_irqrestore(&dev->misc_lock, flags);
}

static void ns83820_do_isr(struct net_device *ndev, u32 isr);
static irqreturn_t ns83820_irq(int foo, void *data)
{
        struct net_device *ndev = data;
        struct ns83820 *dev = PRIV(ndev);
        u32 isr;
        dprintk("ns83820_irq(%p)\n", ndev);

        dev->ihr = 0;

        isr = readl(dev->base + ISR);
        dprintk("irq: %08x\n", isr);
        ns83820_do_isr(ndev, isr);
        return IRQ_HANDLED;
}

static void ns83820_do_isr(struct net_device *ndev, u32 isr)
{
        struct ns83820 *dev = PRIV(ndev);
        unsigned long flags;

#ifdef DEBUG
        if (isr & ~(ISR_PHY | ISR_RXDESC | ISR_RXEARLY | ISR_RXOK | ISR_RXERR | ISR_TXIDLE | ISR_TXOK | ISR_TXDESC))
                Dprintk("odd isr? 0x%08x\n", isr);
#endif

        if (ISR_RXIDLE & isr) {
                dev->rx_info.idle = 1;
                Dprintk("oh dear, we are idle\n");
                ns83820_rx_kick(ndev);
        }

        if ((ISR_RXDESC | ISR_RXOK) & isr) {
                prefetch(dev->rx_info.next_rx_desc);

                spin_lock_irqsave(&dev->misc_lock, flags);
                dev->IMR_cache &= ~(ISR_RXDESC | ISR_RXOK);
                writel(dev->IMR_cache, dev->base + IMR);
                spin_unlock_irqrestore(&dev->misc_lock, flags);

                tasklet_schedule(&dev->rx_tasklet);
                //rx_irq(ndev);
                //writel(4, dev->base + IHR);
        }

        if ((ISR_RXIDLE | ISR_RXORN | ISR_RXDESC | ISR_RXOK | ISR_RXERR) & isr)
                ns83820_rx_kick(ndev);

        if (unlikely(ISR_RXSOVR & isr)) {
                //printk("overrun: rxsovr\n");
                dev->stats.rx_fifo_errors ++;
        }

        if (unlikely(ISR_RXORN & isr)) {
                //printk("overrun: rxorn\n");
                dev->stats.rx_fifo_errors ++;
        }

        if ((ISR_RXRCMP & isr) && dev->rx_info.up)
                writel(CR_RXE, dev->base + CR);

        if (ISR_TXIDLE & isr) {
                u32 txdp;
                txdp = readl(dev->base + TXDP);
                dprintk("txdp: %08x\n", txdp);
                txdp -= dev->tx_phy_descs;
                dev->tx_idx = txdp / (DESC_SIZE * 4);
                if (dev->tx_idx >= NR_TX_DESC) {
                        printk(KERN_ALERT "%s: BUG -- txdp out of range\n", ndev->name);
                        dev->tx_idx = 0;
                }
                /* The may have been a race between a pci originated read
                 * and the descriptor update from the cpu.  Just in case,
                 * kick the transmitter if the hardware thinks it is on a
                 * different descriptor than we are.
                 */
                if (dev->tx_idx != dev->tx_free_idx)
                        kick_tx(dev);
        }

        /* Defer tx ring processing until more than a minimum amount of
         * work has accumulated
         */
        if ((ISR_TXDESC | ISR_TXIDLE | ISR_TXOK | ISR_TXERR) & isr) {
                spin_lock_irqsave(&dev->tx_lock, flags);
                do_tx_done(ndev);
                spin_unlock_irqrestore(&dev->tx_lock, flags);

                /* Disable TxOk if there are no outstanding tx packets.
                 */
                if ((dev->tx_done_idx == dev->tx_free_idx) &&
                    (dev->IMR_cache & ISR_TXOK)) {
                        spin_lock_irqsave(&dev->misc_lock, flags);
                        dev->IMR_cache &= ~ISR_TXOK;
                        writel(dev->IMR_cache, dev->base + IMR);
                        spin_unlock_irqrestore(&dev->misc_lock, flags);
                }
        }

        /* The TxIdle interrupt can come in before the transmit has
         * completed.  Normally we reap packets off of the combination
         * of TxDesc and TxIdle and leave TxOk disabled (since it
         * occurs on every packet), but when no further irqs of this
         * nature are expected, we must enable TxOk.
         */
        if ((ISR_TXIDLE & isr) && (dev->tx_done_idx != dev->tx_free_idx)) {
                spin_lock_irqsave(&dev->misc_lock, flags);
                dev->IMR_cache |= ISR_TXOK;
                writel(dev->IMR_cache, dev->base + IMR);
                spin_unlock_irqrestore(&dev->misc_lock, flags);
        }

        /* MIB interrupt: one of the statistics counters is about to overflow */
        if (unlikely(ISR_MIB & isr))
                ns83820_mib_isr(dev);

        /* PHY: Link up/down/negotiation state change */
        if (unlikely(ISR_PHY & isr))
                phy_intr(ndev);

#if 0        /* Still working on the interrupt mitigation strategy */
        if (dev->ihr)
                writel(dev->ihr, dev->base + IHR);
#endif
}

static void ns83820_do_reset(struct ns83820 *dev, u32 which)
{
        Dprintk("resetting chip...\n");
        writel(which, dev->base + CR);
        do {
                schedule();
        } while (readl(dev->base + CR) & which);
        Dprintk("okay!\n");
}

static int ns83820_stop(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);

        /* FIXME: protect against interrupt handler? */
        del_timer_sync(&dev->tx_watchdog);

        /* disable interrupts */
        writel(0, dev->base + IMR);
        writel(0, dev->base + IER);
        readl(dev->base + IER);

        dev->rx_info.up = 0;
        synchronize_irq(dev->pci_dev->irq);

        ns83820_do_reset(dev, CR_RST);

        synchronize_irq(dev->pci_dev->irq);

        spin_lock_irq(&dev->misc_lock);
        dev->IMR_cache &= ~(ISR_TXURN | ISR_TXIDLE | ISR_TXERR | ISR_TXDESC | ISR_TXOK);
        spin_unlock_irq(&dev->misc_lock);

        ns83820_cleanup_rx(dev);
        ns83820_cleanup_tx(dev);

        return 0;
}

static void ns83820_tx_timeout(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        u32 tx_done_idx;
        __le32 *desc;
        unsigned long flags;

        spin_lock_irqsave(&dev->tx_lock, flags);

        tx_done_idx = dev->tx_done_idx;
        desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);

        printk(KERN_INFO "%s: tx_timeout: tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
                ndev->name,
                tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));

#if defined(DEBUG)
        {
                u32 isr;
                isr = readl(dev->base + ISR);
                printk("irq: %08x imr: %08x\n", isr, dev->IMR_cache);
                ns83820_do_isr(ndev, isr);
        }
#endif

        do_tx_done(ndev);

        tx_done_idx = dev->tx_done_idx;
        desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);

        printk(KERN_INFO "%s: after: tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
                ndev->name,
                tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));

        spin_unlock_irqrestore(&dev->tx_lock, flags);
}

static void ns83820_tx_watch(unsigned long data)
{
        struct net_device *ndev = (void *)data;
        struct ns83820 *dev = PRIV(ndev);

#if defined(DEBUG)
        printk("ns83820_tx_watch: %u %u %d\n",
                dev->tx_done_idx, dev->tx_free_idx, atomic_read(&dev->nr_tx_skbs)
                );
#endif

        if (time_after(jiffies, ndev->trans_start + 1*HZ) &&
            dev->tx_done_idx != dev->tx_free_idx) {
                printk(KERN_DEBUG "%s: ns83820_tx_watch: %u %u %d\n",
                        ndev->name,
                        dev->tx_done_idx, dev->tx_free_idx,
                        atomic_read(&dev->nr_tx_skbs));
                ns83820_tx_timeout(ndev);
        }

        mod_timer(&dev->tx_watchdog, jiffies + 2*HZ);
}

static int ns83820_open(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        unsigned i;
        u32 desc;
        int ret;

        dprintk("ns83820_open\n");

        writel(0, dev->base + PQCR);

        ret = ns83820_setup_rx(ndev);
        if (ret)
                goto failed;

        memset(dev->tx_descs, 0, 4 * NR_TX_DESC * DESC_SIZE);
        for (i=0; i<NR_TX_DESC; i++) {
                dev->tx_descs[(i * DESC_SIZE) + DESC_LINK]
                                = cpu_to_le32(
                                  dev->tx_phy_descs
                                  + ((i+1) % NR_TX_DESC) * DESC_SIZE * 4);
        }

        dev->tx_idx = 0;
        dev->tx_done_idx = 0;
        desc = dev->tx_phy_descs;
        writel(0, dev->base + TXDP_HI);
        writel(desc, dev->base + TXDP);

        init_timer(&dev->tx_watchdog);
        dev->tx_watchdog.data = (unsigned long)ndev;
        dev->tx_watchdog.function = ns83820_tx_watch;
        mod_timer(&dev->tx_watchdog, jiffies + 2*HZ);

        netif_start_queue(ndev);        /* FIXME: wait for phy to come up */

        return 0;

failed:
        ns83820_stop(ndev);
        return ret;
}

static void ns83820_getmac(struct ns83820 *dev, u8 *mac)
{
        unsigned i;
        for (i=0; i<3; i++) {
                u32 data;

                /* Read from the perfect match memory: this is loaded by
                 * the chip from the EEPROM via the EELOAD self test.
                 */
                writel(i*2, dev->base + RFCR);
                data = readl(dev->base + RFDR);

                *mac++ = data;
                *mac++ = data >> 8;
        }
}

static int ns83820_change_mtu(struct net_device *ndev, int new_mtu)
{
        if (new_mtu > RX_BUF_SIZE)
                return -EINVAL;
        ndev->mtu = new_mtu;
        return 0;
}

static void ns83820_set_multicast(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        u8 __iomem *rfcr = dev->base + RFCR;
        u32 and_mask = 0xffffffff;
        u32 or_mask = 0;
        u32 val;

        if (ndev->flags & IFF_PROMISC)
                or_mask |= RFCR_AAU | RFCR_AAM;
        else
                and_mask &= ~(RFCR_AAU | RFCR_AAM);

        if (ndev->flags & IFF_ALLMULTI || ndev->mc_count)
                or_mask |= RFCR_AAM;
        else
                and_mask &= ~RFCR_AAM;

        spin_lock_irq(&dev->misc_lock);
        val = (readl(rfcr) & and_mask) | or_mask;
        /* Ramit : RFCR Write Fix doc says RFEN must be 0 modify other bits */
        writel(val & ~RFCR_RFEN, rfcr);
        writel(val, rfcr);
        spin_unlock_irq(&dev->misc_lock);
}

static void ns83820_run_bist(struct net_device *ndev, const char *name, u32 enable, u32 done, u32 fail)
{
        struct ns83820 *dev = PRIV(ndev);
        int timed_out = 0;
        unsigned long start;
        u32 status;
        int loops = 0;

        dprintk("%s: start %s\n", ndev->name, name);

        start = jiffies;

        writel(enable, dev->base + PTSCR);
        for (;;) {
                loops++;
                status = readl(dev->base + PTSCR);
                if (!(status & enable))
                        break;
                if (status & done)
                        break;
                if (status & fail)
                        break;
                if (time_after_eq(jiffies, start + HZ)) {
                        timed_out = 1;
                        break;
                }
                schedule_timeout_uninterruptible(1);
        }

        if (status & fail)
                printk(KERN_INFO "%s: %s failed! (0x%08x & 0x%08x)\n",
                        ndev->name, name, status, fail);
        else if (timed_out)
                printk(KERN_INFO "%s: run_bist %s timed out! (%08x)\n",
                        ndev->name, name, status);

        dprintk("%s: done %s in %d loops\n", ndev->name, name, loops);
}

#ifdef PHY_CODE_IS_FINISHED
static void ns83820_mii_write_bit(struct ns83820 *dev, int bit)
{
        /* drive MDC low */
        dev->MEAR_cache &= ~MEAR_MDC;
        writel(dev->MEAR_cache, dev->base + MEAR);
        readl(dev->base + MEAR);

        /* enable output, set bit */
        dev->MEAR_cache |= MEAR_MDDIR;
        if (bit)
                dev->MEAR_cache |= MEAR_MDIO;
        else
                dev->MEAR_cache &= ~MEAR_MDIO;

        /* set the output bit */
        writel(dev->MEAR_cache, dev->base + MEAR);
        readl(dev->base + MEAR);

        /* Wait.  Max clock rate is 2.5MHz, this way we come in under 1MHz */
        udelay(1);

        /* drive MDC high causing the data bit to be latched */
        dev->MEAR_cache |= MEAR_MDC;
        writel(dev->MEAR_cache, dev->base + MEAR);
        readl(dev->base + MEAR);

        /* Wait again... */
        udelay(1);
}

static int ns83820_mii_read_bit(struct ns83820 *dev)
{
        int bit;

        /* drive MDC low, disable output */
        dev->MEAR_cache &= ~MEAR_MDC;
        dev->MEAR_cache &= ~MEAR_MDDIR;
        writel(dev->MEAR_cache, dev->base + MEAR);
        readl(dev->base + MEAR);

        /* Wait.  Max clock rate is 2.5MHz, this way we come in under 1MHz */
        udelay(1);

        /* drive MDC high causing the data bit to be latched */
        bit = (readl(dev->base + MEAR) & MEAR_MDIO) ? 1 : 0;
        dev->MEAR_cache |= MEAR_MDC;
        writel(dev->MEAR_cache, dev->base + MEAR);

        /* Wait again... */
        udelay(1);

        return bit;
}

static unsigned ns83820_mii_read_reg(struct ns83820 *dev, unsigned phy, unsigned reg)
{
        unsigned data = 0;
        int i;

        /* read some garbage so that we eventually sync up */
        for (i=0; i<64; i++)
                ns83820_mii_read_bit(dev);

        ns83820_mii_write_bit(dev, 0);        /* start */
        ns83820_mii_write_bit(dev, 1);
        ns83820_mii_write_bit(dev, 1);        /* opcode read */
        ns83820_mii_write_bit(dev, 0);

        /* write out the phy address: 5 bits, msb first */
        for (i=0; i<5; i++)
                ns83820_mii_write_bit(dev, phy & (0x10 >> i));

        /* write out the register address, 5 bits, msb first */
        for (i=0; i<5; i++)
                ns83820_mii_write_bit(dev, reg & (0x10 >> i));

        ns83820_mii_read_bit(dev);        /* turn around cycles */
        ns83820_mii_read_bit(dev);

        /* read in the register data, 16 bits msb first */
        for (i=0; i<16; i++) {
                data <<= 1;
                data |= ns83820_mii_read_bit(dev);
        }

        return data;
}

static unsigned ns83820_mii_write_reg(struct ns83820 *dev, unsigned phy, unsigned reg, unsigned data)
{
        int i;

        /* read some garbage so that we eventually sync up */
        for (i=0; i<64; i++)
                ns83820_mii_read_bit(dev);

        ns83820_mii_write_bit(dev, 0);        /* start */
        ns83820_mii_write_bit(dev, 1);
        ns83820_mii_write_bit(dev, 0);        /* opcode read */
        ns83820_mii_write_bit(dev, 1);

        /* write out the phy address: 5 bits, msb first */
        for (i=0; i<5; i++)
                ns83820_mii_write_bit(dev, phy & (0x10 >> i));

        /* write out the register address, 5 bits, msb first */
        for (i=0; i<5; i++)
                ns83820_mii_write_bit(dev, reg & (0x10 >> i));

        ns83820_mii_read_bit(dev);        /* turn around cycles */
        ns83820_mii_read_bit(dev);

        /* read in the register data, 16 bits msb first */
        for (i=0; i<16; i++)
                ns83820_mii_write_bit(dev, (data >> (15 - i)) & 1);

        return data;
}

static void ns83820_probe_phy(struct net_device *ndev)
{
        struct ns83820 *dev = PRIV(ndev);
        static int first;
        int i;
#define MII_PHYIDR1        0x02
#define MII_PHYIDR2        0x03

#if 0
        if (!first) {
                unsigned tmp;
                ns83820_mii_read_reg(dev, 1, 0x09);
                ns83820_mii_write_reg(dev, 1, 0x10, 0x0d3e);

                tmp = ns83820_mii_read_reg(dev, 1, 0x00);
                ns83820_mii_write_reg(dev, 1, 0x00, tmp | 0x8000);
                udelay(1300);
                ns83820_mii_read_reg(dev, 1, 0x09);
        }
#endif
        first = 1;

        for (i=1; i<2; i++) {
                int j;
                unsigned a, b;
                a = ns83820_mii_read_reg(dev, i, MII_PHYIDR1);
                b = ns83820_mii_read_reg(dev, i, MII_PHYIDR2);

                //printk("%s: phy %d: 0x%04x 0x%04x\n",
                //        ndev->name, i, a, b);

                for (j=0; j<0x16; j+=4) {
                        dprintk("%s: [0x%02x] %04x %04x %04x %04x\n",
                                ndev->name, j,
                                ns83820_mii_read_reg(dev, i, 0 + j),
                                ns83820_mii_read_reg(dev, i, 1 + j),
                                ns83820_mii_read_reg(dev, i, 2 + j),
                                ns83820_mii_read_reg(dev, i, 3 + j)
                                );
                }
        }
        {
                unsigned a, b;
                /* read firmware version: memory addr is 0x8402 and 0x8403 */
                ns83820_mii_write_reg(dev, 1, 0x16, 0x000d);
                ns83820_mii_write_reg(dev, 1, 0x1e, 0x810e);
                a = ns83820_mii_read_reg(dev, 1, 0x1d);

                ns83820_mii_write_reg(dev, 1, 0x16, 0x000d);
                ns83820_mii_write_reg(dev, 1, 0x1e, 0x810e);
                b = ns83820_mii_read_reg(dev, 1, 0x1d);
                dprintk("version: 0x%04x 0x%04x\n", a, b);
        }
}
#endif

static int __devinit ns83820_init_one(struct pci_dev *pci_dev, const struct pci_device_id *id)
{
        struct net_device *ndev;
        struct ns83820 *dev;
        long addr;
        int err;
        int using_dac = 0;
        DECLARE_MAC_BUF(mac);

        /* See if we can set the dma mask early on; failure is fatal. */
        if (sizeof(dma_addr_t) == 8 &&
                 !pci_set_dma_mask(pci_dev, DMA_64BIT_MASK)) {
                using_dac = 1;
        } else if (!pci_set_dma_mask(pci_dev, DMA_32BIT_MASK)) {
                using_dac = 0;
        } else {
                dev_warn(&pci_dev->dev, "pci_set_dma_mask failed!\n");
                return -ENODEV;
        }

        ndev = alloc_etherdev(sizeof(struct ns83820));
        dev = PRIV(ndev);

        err = -ENOMEM;
        if (!dev)
                goto out;

        dev->ndev = ndev;

        spin_lock_init(&dev->rx_info.lock);
        spin_lock_init(&dev->tx_lock);
        spin_lock_init(&dev->misc_lock);
        dev->pci_dev = pci_dev;

        SET_NETDEV_DEV(ndev, &pci_dev->dev);

        INIT_WORK(&dev->tq_refill, queue_refill);
        tasklet_init(&dev->rx_tasklet, rx_action, (unsigned long)ndev);

        err = pci_enable_device(pci_dev);
        if (err) {
                dev_info(&pci_dev->dev, "pci_enable_dev failed: %d\n", err);
                goto out_free;
        }

        pci_set_master(pci_dev);
        addr = pci_resource_start(pci_dev, 1);
        dev->base = ioremap_nocache(addr, PAGE_SIZE);
        dev->tx_descs = pci_alloc_consistent(pci_dev,
                        4 * DESC_SIZE * NR_TX_DESC, &dev->tx_phy_descs);
        dev->rx_info.descs = pci_alloc_consistent(pci_dev,
                        4 * DESC_SIZE * NR_RX_DESC, &dev->rx_info.phy_descs);
        err = -ENOMEM;
        if (!dev->base || !dev->tx_descs || !dev->rx_info.descs)
                goto out_disable;

        dprintk("%p: %08lx  %p: %08lx\n",
                dev->tx_descs, (long)dev->tx_phy_descs,
                dev->rx_info.descs, (long)dev->rx_info.phy_descs);

        /* disable interrupts */
        writel(0, dev->base + IMR);
        writel(0, dev->base + IER);
        readl(dev->base + IER);

        dev->IMR_cache = 0;

        err = request_irq(pci_dev->irq, ns83820_irq, IRQF_SHARED,
                          DRV_NAME, ndev);
        if (err) {
                dev_info(&pci_dev->dev, "unable to register irq %d, err %d\n",
                        pci_dev->irq, err);
                goto out_disable;
        }

        /*
         * FIXME: we are holding rtnl_lock() over obscenely long area only
         * because some of the setup code uses dev->name.  It's Wrong(tm) -
         * we should be using driver-specific names for all that stuff.
         * For now that will do, but we really need to come back and kill
         * most of the dev_alloc_name() users later.
         */
        rtnl_lock();
        err = dev_alloc_name(ndev, ndev->name);
        if (err < 0) {
                dev_info(&pci_dev->dev, "unable to get netdev name: %d\n", err);
                goto out_free_irq;
        }

        printk("%s: ns83820.c: 0x22c: %08x, subsystem: %04x:%04x\n",
                ndev->name, le32_to_cpu(readl(dev->base + 0x22c)),
                pci_dev->subsystem_vendor, pci_dev->subsystem_device);

        ndev->open = ns83820_open;
        ndev->stop = ns83820_stop;
        ndev->hard_start_xmit = ns83820_hard_start_xmit;
        ndev->get_stats = ns83820_get_stats;
        ndev->change_mtu = ns83820_change_mtu;
        ndev->set_multicast_list = ns83820_set_multicast;
        SET_ETHTOOL_OPS(ndev, &ops);
        ndev->tx_timeout = ns83820_tx_timeout;
        ndev->watchdog_timeo = 5 * HZ;
        pci_set_drvdata(pci_dev, ndev);

        ns83820_do_reset(dev, CR_RST);

        /* Must reset the ram bist before running it */
        writel(PTSCR_RBIST_RST, dev->base + PTSCR);
        ns83820_run_bist(ndev, "sram bist",   PTSCR_RBIST_EN,
                         PTSCR_RBIST_DONE, PTSCR_RBIST_FAIL);
        ns83820_run_bist(ndev, "eeprom bist", PTSCR_EEBIST_EN, 0,
                         PTSCR_EEBIST_FAIL);
        ns83820_run_bist(ndev, "eeprom load", PTSCR_EELOAD_EN, 0, 0);

        /* I love config registers */
        dev->CFG_cache = readl(dev->base + CFG);

        if ((dev->CFG_cache & CFG_PCI64_DET)) {
                printk(KERN_INFO "%s: detected 64 bit PCI data bus.\n",
                        ndev->name);
                /*dev->CFG_cache |= CFG_DATA64_EN;*/
                if (!(dev->CFG_cache & CFG_DATA64_EN))
                        printk(KERN_INFO "%s: EEPROM did not enable 64 bit bus.  Disabled.\n",
                                ndev->name);
        } else
                dev->CFG_cache &= ~(CFG_DATA64_EN);

        dev->CFG_cache &= (CFG_TBI_EN  | CFG_MRM_DIS   | CFG_MWI_DIS |
                           CFG_T64ADDR | CFG_DATA64_EN | CFG_EXT_125 |
                           CFG_M64ADDR);
        dev->CFG_cache |= CFG_PINT_DUPSTS | CFG_PINT_LNKSTS | CFG_PINT_SPDSTS |
                          CFG_EXTSTS_EN   | CFG_EXD         | CFG_PESEL;
        dev->CFG_cache |= CFG_REQALG;
        dev->CFG_cache |= CFG_POW;
        dev->CFG_cache |= CFG_TMRTEST;

        /* When compiled with 64 bit addressing, we must always enable
         * the 64 bit descriptor format.
         */
        if (sizeof(dma_addr_t) == 8)
                dev->CFG_cache |= CFG_M64ADDR;
        if (using_dac)
                dev->CFG_cache |= CFG_T64ADDR;

        /* Big endian mode does not seem to do what the docs suggest */
        dev->CFG_cache &= ~CFG_BEM;

        /* setup optical transceiver if we have one */
        if (dev->CFG_cache & CFG_TBI_EN) {
                printk(KERN_INFO "%s: enabling optical transceiver\n",
                        ndev->name);
                writel(readl(dev->base + GPIOR) | 0x3e8, dev->base + GPIOR);

                /* setup auto negotiation feature advertisement */
                writel(readl(dev->base + TANAR)
                       | TANAR_HALF_DUP | TANAR_FULL_DUP,
                       dev->base + TANAR);

                /* start auto negotiation */
                writel(TBICR_MR_AN_ENABLE | TBICR_MR_RESTART_AN,
                       dev->base + TBICR);
                writel(TBICR_MR_AN_ENABLE, dev->base + TBICR);
                dev->linkstate = LINK_AUTONEGOTIATE;

                dev->CFG_cache |= CFG_MODE_1000;
        }

        writel(dev->CFG_cache, dev->base + CFG);
        dprintk("CFG: %08x\n", dev->CFG_cache);

        if (reset_phy) {
                printk(KERN_INFO "%s: resetting phy\n", ndev->name);
                writel(dev->CFG_cache | CFG_PHY_RST, dev->base + CFG);
                msleep(10);
                writel(dev->CFG_cache, dev->base + CFG);
        }

#if 0        /* Huh?  This sets the PCI latency register.  Should be done via
         * the PCI layer.  FIXME.
         */
        if (readl(dev->base + SRR))
                writel(readl(dev->base+0x20c) | 0xfe00, dev->base + 0x20c);
#endif

        /* Note!  The DMA burst size interacts with packet
         * transmission, such that the largest packet that
         * can be transmitted is 8192 - FLTH - burst size.
         * If only the transmit fifo was larger...
         */
        /* Ramit : 1024 DMA is not a good idea, it ends up banging
         * some DELL and COMPAQ SMP systems */
        writel(TXCFG_CSI | TXCFG_HBI | TXCFG_ATP | TXCFG_MXDMA512
                | ((1600 / 32) * 0x100),
                dev->base + TXCFG);

        /* Flush the interrupt holdoff timer */
        writel(0x000, dev->base + IHR);
        writel(0x100, dev->base + IHR);
        writel(0x000, dev->base + IHR);

        /* Set Rx to full duplex, don't accept runt, errored, long or length
         * range errored packets.  Use 512 byte DMA.
         */
        /* Ramit : 1024 DMA is not a good idea, it ends up banging
         * some DELL and COMPAQ SMP systems
         * Turn on ALP, only we are accpeting Jumbo Packets */
        writel(RXCFG_AEP | RXCFG_ARP | RXCFG_AIRL | RXCFG_RX_FD
                | RXCFG_STRIPCRC
                //| RXCFG_ALP
                | (RXCFG_MXDMA512) | 0, dev->base + RXCFG);

        /* Disable priority queueing */
        writel(0, dev->base + PQCR);

        /* Enable IP checksum validation and detetion of VLAN headers.
         * Note: do not set the reject options as at least the 0x102
         * revision of the chip does not properly accept IP fragments
         * at least for UDP.
         */
        /* Ramit : Be sure to turn on RXCFG_ARP if VLAN's are enabled, since
         * the MAC it calculates the packetsize AFTER stripping the VLAN
         * header, and if a VLAN Tagged packet of 64 bytes is received (like
         * a ping with a VLAN header) then the card, strips the 4 byte VLAN
         * tag and then checks the packet size, so if RXCFG_ARP is not enabled,
         * it discrards it!.  These guys......
         * also turn on tag stripping if hardware acceleration is enabled
         */
#ifdef NS83820_VLAN_ACCEL_SUPPORT
#define VRCR_INIT_VALUE (VRCR_IPEN|VRCR_VTDEN|VRCR_VTREN)
#else
#define VRCR_INIT_VALUE (VRCR_IPEN|VRCR_VTDEN)
#endif
        writel(VRCR_INIT_VALUE, dev->base + VRCR);

        /* Enable per-packet TCP/UDP/IP checksumming
         * and per packet vlan tag insertion if
         * vlan hardware acceleration is enabled
         */
#ifdef NS83820_VLAN_ACCEL_SUPPORT
#define VTCR_INIT_VALUE (VTCR_PPCHK|VTCR_VPPTI)
#else
#define VTCR_INIT_VALUE VTCR_PPCHK
#endif
        writel(VTCR_INIT_VALUE, dev->base + VTCR);

        /* Ramit : Enable async and sync pause frames */
        /* writel(0, dev->base + PCR); */
        writel((PCR_PS_MCAST | PCR_PS_DA | PCR_PSEN | PCR_FFLO_4K |
                PCR_FFHI_8K | PCR_STLO_4 | PCR_STHI_8 | PCR_PAUSE_CNT),
                dev->base + PCR);

        /* Disable Wake On Lan */
        writel(0, dev->base + WCSR);

        ns83820_getmac(dev, ndev->dev_addr);

        /* Yes, we support dumb IP checksum on transmit */
        ndev->features |= NETIF_F_SG;
        ndev->features |= NETIF_F_IP_CSUM;

#ifdef NS83820_VLAN_ACCEL_SUPPORT
        /* We also support hardware vlan acceleration */
        ndev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
        ndev->vlan_rx_register = ns83820_vlan_rx_register;
#endif

        if (using_dac) {
                printk(KERN_INFO "%s: using 64 bit addressing.\n",
                        ndev->name);
                ndev->features |= NETIF_F_HIGHDMA;
        }

        printk(KERN_INFO "%s: ns83820 v" VERSION ": DP83820 v%u.%u: %s io=0x%08lx irq=%d f=%s\n",
                ndev->name,
                (unsigned)readl(dev->base + SRR) >> 8,
                (unsigned)readl(dev->base + SRR) & 0xff,
                print_mac(mac, ndev->dev_addr),
                addr, pci_dev->irq,
                (ndev->features & NETIF_F_HIGHDMA) ? "h,sg" : "sg"
                );

#ifdef PHY_CODE_IS_FINISHED
        ns83820_probe_phy(ndev);
#endif

        err = register_netdevice(ndev);
        if (err) {
                printk(KERN_INFO "ns83820: unable to register netdev: %d\n", err);
                goto out_cleanup;
        }
        rtnl_unlock();

        return 0;

out_cleanup:
        writel(0, dev->base + IMR);        /* paranoia */
        writel(0, dev->base + IER);
        readl(dev->base + IER);
out_free_irq:
        rtnl_unlock();
        free_irq(pci_dev->irq, ndev);
out_disable:
        if (dev->base)
                iounmap(dev->base);
        pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_TX_DESC, dev->tx_descs, dev->tx_phy_descs);
        pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_RX_DESC, dev->rx_info.descs, dev->rx_info.phy_descs);
        pci_disable_device(pci_dev);
out_free:
        free_netdev(ndev);
        pci_set_drvdata(pci_dev, NULL);
out:
        return err;
}

static void __devexit ns83820_remove_one(struct pci_dev *pci_dev)
{
        struct net_device *ndev = pci_get_drvdata(pci_dev);
        struct ns83820 *dev = PRIV(ndev); /* ok even if NULL */

        if (!ndev)                        /* paranoia */
                return;

        writel(0, dev->base + IMR);        /* paranoia */
        writel(0, dev->base + IER);
        readl(dev->base + IER);

        unregister_netdev(ndev);
        free_irq(dev->pci_dev->irq, ndev);
        iounmap(dev->base);
        pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_TX_DESC,
                        dev->tx_descs, dev->tx_phy_descs);
        pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_RX_DESC,
                        dev->rx_info.descs, dev->rx_info.phy_descs);
        pci_disable_device(dev->pci_dev);
        free_netdev(ndev);
        pci_set_drvdata(pci_dev, NULL);
}

static struct pci_device_id ns83820_pci_tbl[] = {
        { 0x100b, 0x0022, PCI_ANY_ID, PCI_ANY_ID, 0, .driver_data = 0, },
        { 0, },
};

static struct pci_driver driver = {
        .name                = "ns83820",
        .id_table        = ns83820_pci_tbl,
        .probe                = ns83820_init_one,
        .remove                = __devexit_p(ns83820_remove_one),
#if 0        /* FIXME: implement */
        .suspend        = ,
        .resume                = ,
#endif
};


static int __init ns83820_init(void)
{
        printk(KERN_INFO "ns83820.c: National Semiconductor DP83820 10/100/1000 driver.\n");
        return pci_register_driver(&driver);
}

static void __exit ns83820_exit(void)
{
        pci_unregister_driver(&driver);
}

MODULE_AUTHOR("Benjamin LaHaise <bcrl@kvack.org>");
MODULE_DESCRIPTION("National Semiconductor DP83820 10/100/1000 driver");
MODULE_LICENSE("GPL");

MODULE_DEVICE_TABLE(pci, ns83820_pci_tbl);

module_param(lnksts, int, 0);
MODULE_PARM_DESC(lnksts, "Polarity of LNKSTS bit");

module_param(ihr, int, 0);
MODULE_PARM_DESC(ihr, "Time in 100 us increments to delay interrupts (range 0-127)");

module_param(reset_phy, int, 0);
MODULE_PARM_DESC(reset_phy, "Set to 1 to reset the PHY on startup");

module_init(ns83820_init);
module_exit(ns83820_exit);