git.oblomov.eu Git - linux-2.6/blob - drivers/net/tulip/interrupt.c

   1 /*
   2         drivers/net/tulip/interrupt.c
   3
   4         Maintained by Jeff Garzik <jgarzik@pobox.com>
   5         Copyright 2000,2001  The Linux Kernel Team
   6         Written/copyright 1994-2001 by Donald Becker.
   7
   8         This software may be used and distributed according to the terms
   9         of the GNU General Public License, incorporated herein by reference.
  10
  11         Please refer to Documentation/DocBook/tulip-user.{pdf,ps,html}
  12         for more information on this driver, or visit the project
  13         Web page at http://sourceforge.net/projects/tulip/
  14
  15 */
  16
  17 #include <linux/pci.h>
  18 #include "tulip.h"
  19 #include <linux/config.h>
  20 #include <linux/etherdevice.h>
  21
  22 int tulip_rx_copybreak;
  23 unsigned int tulip_max_interrupt_work;
  24
  25 #ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
  26 #define MIT_SIZE 15
  27 #define MIT_TABLE 15 /* We use 0 or max */
  28
  29 static unsigned int mit_table[MIT_SIZE+1] =
  30 {
  31         /*  CRS11 21143 hardware Mitigation Control Interrupt
  32             We use only RX mitigation we other techniques for
  33             TX intr. mitigation.
  34
  35            31    Cycle Size (timer control)
  36            30:27 TX timer in 16 * Cycle size
  37            26:24 TX No pkts before Int.
  38            23:20 RX timer in Cycle size
  39            19:17 RX No pkts before Int.
  40            16       Continues Mode (CM)
  41         */
  42
  43         0x0,             /* IM disabled */
  44         0x80150000,      /* RX time = 1, RX pkts = 2, CM = 1 */
  45         0x80150000,
  46         0x80270000,
  47         0x80370000,
  48         0x80490000,
  49         0x80590000,
  50         0x80690000,
  51         0x807B0000,
  52         0x808B0000,
  53         0x809D0000,
  54         0x80AD0000,
  55         0x80BD0000,
  56         0x80CF0000,
  57         0x80DF0000,
  58 //       0x80FF0000      /* RX time = 16, RX pkts = 7, CM = 1 */
  59         0x80F10000      /* RX time = 16, RX pkts = 0, CM = 1 */
  60 };
  61 #endif
  62
  63
  64 int tulip_refill_rx(struct net_device *dev)
  65 {
  66         struct tulip_private *tp = netdev_priv(dev);
  67         int entry;
  68         int refilled = 0;
  69
  70         /* Refill the Rx ring buffers. */
  71         for (; tp->cur_rx - tp->dirty_rx > 0; tp->dirty_rx++) {
  72                 entry = tp->dirty_rx % RX_RING_SIZE;
  73                 if (tp->rx_buffers[entry].skb == NULL) {
  74                         struct sk_buff *skb;
  75                         dma_addr_t mapping;
  76
  77                         skb = tp->rx_buffers[entry].skb = dev_alloc_skb(PKT_BUF_SZ);
  78                         if (skb == NULL)
  79                                 break;
  80
  81                         mapping = pci_map_single(tp->pdev, skb->data, PKT_BUF_SZ,
  82                                                  PCI_DMA_FROMDEVICE);
  83                         tp->rx_buffers[entry].mapping = mapping;
  84
  85                         skb->dev = dev;                 /* Mark as being used by this device. */
  86                         tp->rx_ring[entry].buffer1 = cpu_to_le32(mapping);
  87                         refilled++;
  88                 }
  89                 tp->rx_ring[entry].status = cpu_to_le32(DescOwned);
  90         }
  91         if(tp->chip_id == LC82C168) {
  92                 if(((ioread32(tp->base_addr + CSR5)>>17)&0x07) == 4) {
  93                         /* Rx stopped due to out of buffers,
  94                          * restart it
  95                          */
  96                         iowrite32(0x01, tp->base_addr + CSR2);
  97                 }
  98         }
  99         return refilled;
 100 }
 101
 102 #ifdef CONFIG_TULIP_NAPI
 103
 104 void oom_timer(unsigned long data)
 105 {
 106         struct net_device *dev = (struct net_device *)data;
 107         netif_rx_schedule(dev);
 108 }
 109
 110 int tulip_poll(struct net_device *dev, int *budget)
 111 {
 112         struct tulip_private *tp = netdev_priv(dev);
 113         int entry = tp->cur_rx % RX_RING_SIZE;
 114         int rx_work_limit = *budget;
 115         int received = 0;
 116
 117         if (!netif_running(dev))
 118                 goto done;
 119
 120         if (rx_work_limit > dev->quota)
 121                 rx_work_limit = dev->quota;
 122
 123 #ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
 124
 125 /* that one buffer is needed for mit activation; or might be a
 126    bug in the ring buffer code; check later -- JHS*/
 127
 128         if (rx_work_limit >=RX_RING_SIZE) rx_work_limit--;
 129 #endif
 130
 131         if (tulip_debug > 4)
 132                 printk(KERN_DEBUG " In tulip_rx(), entry %d %8.8x.\n", entry,
 133                            tp->rx_ring[entry].status);
 134
 135        do {
 136                 if (ioread32(tp->base_addr + CSR5) == 0xffffffff) {
 137                         printk(KERN_DEBUG " In tulip_poll(), hardware disappeared.\n");
 138                         break;
 139                 }
 140                /* Acknowledge current RX interrupt sources. */
 141                iowrite32((RxIntr | RxNoBuf), tp->base_addr + CSR5);
 142
 143
 144                /* If we own the next entry, it is a new packet. Send it up. */
 145                while ( ! (tp->rx_ring[entry].status & cpu_to_le32(DescOwned))) {
 146                        s32 status = le32_to_cpu(tp->rx_ring[entry].status);
 147
 148
 149                        if (tp->dirty_rx + RX_RING_SIZE == tp->cur_rx)
 150                                break;
 151
 152                        if (tulip_debug > 5)
 153                                printk(KERN_DEBUG "%s: In tulip_rx(), entry %d %8.8x.\n",
 154                                       dev->name, entry, status);
 155                        if (--rx_work_limit < 0)
 156                                goto not_done;
 157
 158                        if ((status & 0x38008300) != 0x0300) {
 159                                if ((status & 0x38000300) != 0x0300) {
 160                                 /* Ingore earlier buffers. */
 161                                        if ((status & 0xffff) != 0x7fff) {
 162                                                if (tulip_debug > 1)
 163                                                        printk(KERN_WARNING "%s: Oversized Ethernet frame "
 164                                                               "spanned multiple buffers, status %8.8x!\n",
 165                                                               dev->name, status);
 166                                                tp->stats.rx_length_errors++;
 167                                        }
 168                                } else if (status & RxDescFatalErr) {
 169                                 /* There was a fatal error. */
 170                                        if (tulip_debug > 2)
 171                                                printk(KERN_DEBUG "%s: Receive error, Rx status %8.8x.\n",
 172                                                       dev->name, status);
 173                                        tp->stats.rx_errors++; /* end of a packet.*/
 174                                        if (status & 0x0890) tp->stats.rx_length_errors++;
 175                                        if (status & 0x0004) tp->stats.rx_frame_errors++;
 176                                        if (status & 0x0002) tp->stats.rx_crc_errors++;
 177                                        if (status & 0x0001) tp->stats.rx_fifo_errors++;
 178                                }
 179                        } else {
 180                                /* Omit the four octet CRC from the length. */
 181                                short pkt_len = ((status >> 16) & 0x7ff) - 4;
 182                                struct sk_buff *skb;
 183
 184 #ifndef final_version
 185                                if (pkt_len > 1518) {
 186                                        printk(KERN_WARNING "%s: Bogus packet size of %d (%#x).\n",
 187                                               dev->name, pkt_len, pkt_len);
 188                                        pkt_len = 1518;
 189                                        tp->stats.rx_length_errors++;
 190                                }
 191 #endif
 192                                /* Check if the packet is long enough to accept without copying
 193                                   to a minimally-sized skbuff. */
 194                                if (pkt_len < tulip_rx_copybreak
 195                                    && (skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
 196                                        skb->dev = dev;
 197                                        skb_reserve(skb, 2);    /* 16 byte align the IP header */
 198                                        pci_dma_sync_single_for_cpu(tp->pdev,
 199                                                                    tp->rx_buffers[entry].mapping,
 200                                                                    pkt_len, PCI_DMA_FROMDEVICE);
 201 #if ! defined(__alpha__)
 202                                        eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->data,
 203                                                         pkt_len, 0);
 204                                        skb_put(skb, pkt_len);
 205 #else
 206                                        memcpy(skb_put(skb, pkt_len),
 207                                               tp->rx_buffers[entry].skb->data,
 208                                               pkt_len);
 209 #endif
 210                                        pci_dma_sync_single_for_device(tp->pdev,
 211                                                                       tp->rx_buffers[entry].mapping,
 212                                                                       pkt_len, PCI_DMA_FROMDEVICE);
 213                                } else {        /* Pass up the skb already on the Rx ring. */
 214                                        char *temp = skb_put(skb = tp->rx_buffers[entry].skb,
 215                                                             pkt_len);
 216
 217 #ifndef final_version
 218                                        if (tp->rx_buffers[entry].mapping !=
 219                                            le32_to_cpu(tp->rx_ring[entry].buffer1)) {
 220                                                printk(KERN_ERR "%s: Internal fault: The skbuff addresses "
 221                                                       "do not match in tulip_rx: %08x vs. %08llx %p / %p.\n",
 222                                                       dev->name,
 223                                                       le32_to_cpu(tp->rx_ring[entry].buffer1),
 224                                                       (unsigned long long)tp->rx_buffers[entry].mapping,
 225                                                       skb->head, temp);
 226                                        }
 227 #endif
 228
 229                                        pci_unmap_single(tp->pdev, tp->rx_buffers[entry].mapping,
 230                                                         PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 231
 232                                        tp->rx_buffers[entry].skb = NULL;
 233                                        tp->rx_buffers[entry].mapping = 0;
 234                                }
 235                                skb->protocol = eth_type_trans(skb, dev);
 236
 237                                netif_receive_skb(skb);
 238
 239                                dev->last_rx = jiffies;
 240                                tp->stats.rx_packets++;
 241                                tp->stats.rx_bytes += pkt_len;
 242                        }
 243                        received++;
 244
 245                        entry = (++tp->cur_rx) % RX_RING_SIZE;
 246                        if (tp->cur_rx - tp->dirty_rx > RX_RING_SIZE/4)
 247                                tulip_refill_rx(dev);
 248
 249                 }
 250
 251                /* New ack strategy... irq does not ack Rx any longer
 252                   hopefully this helps */
 253
 254                /* Really bad things can happen here... If new packet arrives
 255                 * and an irq arrives (tx or just due to occasionally unset
 256                 * mask), it will be acked by irq handler, but new thread
 257                 * is not scheduled. It is major hole in design.
 258                 * No idea how to fix this if "playing with fire" will fail
 259                 * tomorrow (night 011029). If it will not fail, we won
 260                 * finally: amount of IO did not increase at all. */
 261        } while ((ioread32(tp->base_addr + CSR5) & RxIntr));
 262
 263 done:
 264
 265  #ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
 266
 267           /* We use this simplistic scheme for IM. It's proven by
 268              real life installations. We can have IM enabled
 269             continuesly but this would cause unnecessary latency.
 270             Unfortunely we can't use all the NET_RX_* feedback here.
 271             This would turn on IM for devices that is not contributing
 272             to backlog congestion with unnecessary latency.
 273
 274              We monitor the the device RX-ring and have:
 275
 276              HW Interrupt Mitigation either ON or OFF.
 277
 278             ON:  More then 1 pkt received (per intr.) OR we are dropping
 279              OFF: Only 1 pkt received
 280
 281              Note. We only use min and max (0, 15) settings from mit_table */
 282
 283
 284           if( tp->flags &  HAS_INTR_MITIGATION) {
 285                  if( received > 1 ) {
 286                          if( ! tp->mit_on ) {
 287                                  tp->mit_on = 1;
 288                                  iowrite32(mit_table[MIT_TABLE], tp->base_addr + CSR11);
 289                          }
 290                   }
 291                  else {
 292                          if( tp->mit_on ) {
 293                                  tp->mit_on = 0;
 294                                  iowrite32(0, tp->base_addr + CSR11);
 295                          }
 296                   }
 297           }
 298
 299 #endif /* CONFIG_TULIP_NAPI_HW_MITIGATION */
 300
 301          dev->quota -= received;
 302          *budget -= received;
 303
 304          tulip_refill_rx(dev);
 305
 306          /* If RX ring is not full we are out of memory. */
 307          if (tp->rx_buffers[tp->dirty_rx % RX_RING_SIZE].skb == NULL) goto oom;
 308
 309          /* Remove us from polling list and enable RX intr. */
 310
 311          netif_rx_complete(dev);
 312          iowrite32(tulip_tbl[tp->chip_id].valid_intrs, tp->base_addr+CSR7);
 313
 314          /* The last op happens after poll completion. Which means the following:
 315           * 1. it can race with disabling irqs in irq handler
 316           * 2. it can race with dise/enabling irqs in other poll threads
 317           * 3. if an irq raised after beginning loop, it will be immediately
 318           *    triggered here.
 319           *
 320           * Summarizing: the logic results in some redundant irqs both
 321           * due to races in masking and due to too late acking of already
 322           * processed irqs. But it must not result in losing events.
 323           */
 324
 325          return 0;
 326
 327  not_done:
 328          if (!received) {
 329
 330                  received = dev->quota; /* Not to happen */
 331          }
 332          dev->quota -= received;
 333          *budget -= received;
 334
 335          if (tp->cur_rx - tp->dirty_rx > RX_RING_SIZE/2 ||
 336              tp->rx_buffers[tp->dirty_rx % RX_RING_SIZE].skb == NULL)
 337                  tulip_refill_rx(dev);
 338
 339          if (tp->rx_buffers[tp->dirty_rx % RX_RING_SIZE].skb == NULL) goto oom;
 340
 341          return 1;
 342
 343
 344  oom:    /* Executed with RX ints disabled */
 345
 346
 347          /* Start timer, stop polling, but do not enable rx interrupts. */
 348          mod_timer(&tp->oom_timer, jiffies+1);
 349
 350          /* Think: timer_pending() was an explicit signature of bug.
 351           * Timer can be pending now but fired and completed
 352           * before we did netif_rx_complete(). See? We would lose it. */
 353
 354          /* remove ourselves from the polling list */
 355          netif_rx_complete(dev);
 356
 357          return 0;
 358 }
 359
 360 #else /* CONFIG_TULIP_NAPI */
 361
 362 static int tulip_rx(struct net_device *dev)
 363 {
 364         struct tulip_private *tp = netdev_priv(dev);
 365         int entry = tp->cur_rx % RX_RING_SIZE;
 366         int rx_work_limit = tp->dirty_rx + RX_RING_SIZE - tp->cur_rx;
 367         int received = 0;
 368
 369         if (tulip_debug > 4)
 370                 printk(KERN_DEBUG " In tulip_rx(), entry %d %8.8x.\n", entry,
 371                            tp->rx_ring[entry].status);
 372         /* If we own the next entry, it is a new packet. Send it up. */
 373         while ( ! (tp->rx_ring[entry].status & cpu_to_le32(DescOwned))) {
 374                 s32 status = le32_to_cpu(tp->rx_ring[entry].status);
 375
 376                 if (tulip_debug > 5)
 377                         printk(KERN_DEBUG "%s: In tulip_rx(), entry %d %8.8x.\n",
 378                                    dev->name, entry, status);
 379                 if (--rx_work_limit < 0)
 380                         break;
 381                 if ((status & 0x38008300) != 0x0300) {
 382                         if ((status & 0x38000300) != 0x0300) {
 383                                 /* Ingore earlier buffers. */
 384                                 if ((status & 0xffff) != 0x7fff) {
 385                                         if (tulip_debug > 1)
 386                                                 printk(KERN_WARNING "%s: Oversized Ethernet frame "
 387                                                            "spanned multiple buffers, status %8.8x!\n",
 388                                                            dev->name, status);
 389                                         tp->stats.rx_length_errors++;
 390                                 }
 391                         } else if (status & RxDescFatalErr) {
 392                                 /* There was a fatal error. */
 393                                 if (tulip_debug > 2)
 394                                         printk(KERN_DEBUG "%s: Receive error, Rx status %8.8x.\n",
 395                                                    dev->name, status);
 396                                 tp->stats.rx_errors++; /* end of a packet.*/
 397                                 if (status & 0x0890) tp->stats.rx_length_errors++;
 398                                 if (status & 0x0004) tp->stats.rx_frame_errors++;
 399                                 if (status & 0x0002) tp->stats.rx_crc_errors++;
 400                                 if (status & 0x0001) tp->stats.rx_fifo_errors++;
 401                         }
 402                 } else {
 403                         /* Omit the four octet CRC from the length. */
 404                         short pkt_len = ((status >> 16) & 0x7ff) - 4;
 405                         struct sk_buff *skb;
 406
 407 #ifndef final_version
 408                         if (pkt_len > 1518) {
 409                                 printk(KERN_WARNING "%s: Bogus packet size of %d (%#x).\n",
 410                                            dev->name, pkt_len, pkt_len);
 411                                 pkt_len = 1518;
 412                                 tp->stats.rx_length_errors++;
 413                         }
 414 #endif
 415
 416                         /* Check if the packet is long enough to accept without copying
 417                            to a minimally-sized skbuff. */
 418                         if (pkt_len < tulip_rx_copybreak
 419                                 && (skb = dev_alloc_skb(pkt_len + 2)) != NULL) {
 420                                 skb->dev = dev;
 421                                 skb_reserve(skb, 2);    /* 16 byte align the IP header */
 422                                 pci_dma_sync_single_for_cpu(tp->pdev,
 423                                                             tp->rx_buffers[entry].mapping,
 424                                                             pkt_len, PCI_DMA_FROMDEVICE);
 425 #if ! defined(__alpha__)
 426                                 eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->data,
 427                                                  pkt_len, 0);
 428                                 skb_put(skb, pkt_len);
 429 #else
 430                                 memcpy(skb_put(skb, pkt_len),
 431                                        tp->rx_buffers[entry].skb->data,
 432                                        pkt_len);
 433 #endif
 434                                 pci_dma_sync_single_for_device(tp->pdev,
 435                                                                tp->rx_buffers[entry].mapping,
 436                                                                pkt_len, PCI_DMA_FROMDEVICE);
 437                         } else {        /* Pass up the skb already on the Rx ring. */
 438                                 char *temp = skb_put(skb = tp->rx_buffers[entry].skb,
 439                                                      pkt_len);
 440
 441 #ifndef final_version
 442                                 if (tp->rx_buffers[entry].mapping !=
 443                                     le32_to_cpu(tp->rx_ring[entry].buffer1)) {
 444                                         printk(KERN_ERR "%s: Internal fault: The skbuff addresses "
 445                                                "do not match in tulip_rx: %08x vs. %Lx %p / %p.\n",
 446                                                dev->name,
 447                                                le32_to_cpu(tp->rx_ring[entry].buffer1),
 448                                                (long long)tp->rx_buffers[entry].mapping,
 449                                                skb->head, temp);
 450                                 }
 451 #endif
 452
 453                                 pci_unmap_single(tp->pdev, tp->rx_buffers[entry].mapping,
 454                                                  PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 455
 456                                 tp->rx_buffers[entry].skb = NULL;
 457                                 tp->rx_buffers[entry].mapping = 0;
 458                         }
 459                         skb->protocol = eth_type_trans(skb, dev);
 460
 461                         netif_rx(skb);
 462
 463                         dev->last_rx = jiffies;
 464                         tp->stats.rx_packets++;
 465                         tp->stats.rx_bytes += pkt_len;
 466                 }
 467                 received++;
 468                 entry = (++tp->cur_rx) % RX_RING_SIZE;
 469         }
 470         return received;
 471 }
 472 #endif  /* CONFIG_TULIP_NAPI */
 473
 474 static inline unsigned int phy_interrupt (struct net_device *dev)
 475 {
 476 #ifdef __hppa__
 477         struct tulip_private *tp = netdev_priv(dev);
 478         int csr12 = ioread32(tp->base_addr + CSR12) & 0xff;
 479
 480         if (csr12 != tp->csr12_shadow) {
 481                 /* ack interrupt */
 482                 iowrite32(csr12 | 0x02, tp->base_addr + CSR12);
 483                 tp->csr12_shadow = csr12;
 484                 /* do link change stuff */
 485                 spin_lock(&tp->lock);
 486                 tulip_check_duplex(dev);
 487                 spin_unlock(&tp->lock);
 488                 /* clear irq ack bit */
 489                 iowrite32(csr12 & ~0x02, tp->base_addr + CSR12);
 490
 491                 return 1;
 492         }
 493 #endif
 494
 495         return 0;
 496 }
 497
 498 /* The interrupt handler does all of the Rx thread work and cleans up
 499    after the Tx thread. */
 500 irqreturn_t tulip_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
 501 {
 502         struct net_device *dev = (struct net_device *)dev_instance;
 503         struct tulip_private *tp = netdev_priv(dev);
 504         void __iomem *ioaddr = tp->base_addr;
 505         int csr5;
 506         int missed;
 507         int rx = 0;
 508         int tx = 0;
 509         int oi = 0;
 510         int maxrx = RX_RING_SIZE;
 511         int maxtx = TX_RING_SIZE;
 512         int maxoi = TX_RING_SIZE;
 513 #ifdef CONFIG_TULIP_NAPI
 514         int rxd = 0;
 515 #else
 516         int entry;
 517 #endif
 518         unsigned int work_count = tulip_max_interrupt_work;
 519         unsigned int handled = 0;
 520
 521         /* Let's see whether the interrupt really is for us */
 522         csr5 = ioread32(ioaddr + CSR5);
 523
 524         if (tp->flags & HAS_PHY_IRQ)
 525                 handled = phy_interrupt (dev);
 526
 527         if ((csr5 & (NormalIntr|AbnormalIntr)) == 0)
 528                 return IRQ_RETVAL(handled);
 529
 530         tp->nir++;
 531
 532         do {
 533
 534 #ifdef CONFIG_TULIP_NAPI
 535
 536                 if (!rxd && (csr5 & (RxIntr | RxNoBuf))) {
 537                         rxd++;
 538                         /* Mask RX intrs and add the device to poll list. */
 539                         iowrite32(tulip_tbl[tp->chip_id].valid_intrs&~RxPollInt, ioaddr + CSR7);
 540                         netif_rx_schedule(dev);
 541
 542                         if (!(csr5&~(AbnormalIntr|NormalIntr|RxPollInt|TPLnkPass)))
 543                                break;
 544                 }
 545
 546                /* Acknowledge the interrupt sources we handle here ASAP
 547                   the poll function does Rx and RxNoBuf acking */
 548
 549                 iowrite32(csr5 & 0x0001ff3f, ioaddr + CSR5);
 550
 551 #else
 552                 /* Acknowledge all of the current interrupt sources ASAP. */
 553                 iowrite32(csr5 & 0x0001ffff, ioaddr + CSR5);
 554
 555
 556                 if (csr5 & (RxIntr | RxNoBuf)) {
 557                                 rx += tulip_rx(dev);
 558                         tulip_refill_rx(dev);
 559                 }
 560
 561 #endif /*  CONFIG_TULIP_NAPI */
 562
 563                 if (tulip_debug > 4)
 564                         printk(KERN_DEBUG "%s: interrupt  csr5=%#8.8x new csr5=%#8.8x.\n",
 565                                dev->name, csr5, ioread32(ioaddr + CSR5));
 566
 567
 568                 if (csr5 & (TxNoBuf | TxDied | TxIntr | TimerInt)) {
 569                         unsigned int dirty_tx;
 570
 571                         spin_lock(&tp->lock);
 572
 573                         for (dirty_tx = tp->dirty_tx; tp->cur_tx - dirty_tx > 0;
 574                                  dirty_tx++) {
 575                                 int entry = dirty_tx % TX_RING_SIZE;
 576                                 int status = le32_to_cpu(tp->tx_ring[entry].status);
 577
 578                                 if (status < 0)
 579                                         break;                  /* It still has not been Txed */
 580
 581                                 /* Check for Rx filter setup frames. */
 582                                 if (tp->tx_buffers[entry].skb == NULL) {
 583                                         /* test because dummy frames not mapped */
 584                                         if (tp->tx_buffers[entry].mapping)
 585                                                 pci_unmap_single(tp->pdev,
 586                                                          tp->tx_buffers[entry].mapping,
 587                                                          sizeof(tp->setup_frame),
 588                                                          PCI_DMA_TODEVICE);
 589                                         continue;
 590                                 }
 591
 592                                 if (status & 0x8000) {
 593                                         /* There was an major error, log it. */
 594 #ifndef final_version
 595                                         if (tulip_debug > 1)
 596                                                 printk(KERN_DEBUG "%s: Transmit error, Tx status %8.8x.\n",
 597                                                            dev->name, status);
 598 #endif
 599                                         tp->stats.tx_errors++;
 600                                         if (status & 0x4104) tp->stats.tx_aborted_errors++;
 601                                         if (status & 0x0C00) tp->stats.tx_carrier_errors++;
 602                                         if (status & 0x0200) tp->stats.tx_window_errors++;
 603                                         if (status & 0x0002) tp->stats.tx_fifo_errors++;
 604                                         if ((status & 0x0080) && tp->full_duplex == 0)
 605                                                 tp->stats.tx_heartbeat_errors++;
 606                                 } else {
 607                                         tp->stats.tx_bytes +=
 608                                                 tp->tx_buffers[entry].skb->len;
 609                                         tp->stats.collisions += (status >> 3) & 15;
 610                                         tp->stats.tx_packets++;
 611                                 }
 612
 613                                 pci_unmap_single(tp->pdev, tp->tx_buffers[entry].mapping,
 614                                                  tp->tx_buffers[entry].skb->len,
 615                                                  PCI_DMA_TODEVICE);
 616
 617                                 /* Free the original skb. */
 618                                 dev_kfree_skb_irq(tp->tx_buffers[entry].skb);
 619                                 tp->tx_buffers[entry].skb = NULL;
 620                                 tp->tx_buffers[entry].mapping = 0;
 621                                 tx++;
 622                         }
 623
 624 #ifndef final_version
 625                         if (tp->cur_tx - dirty_tx > TX_RING_SIZE) {
 626                                 printk(KERN_ERR "%s: Out-of-sync dirty pointer, %d vs. %d.\n",
 627                                            dev->name, dirty_tx, tp->cur_tx);
 628                                 dirty_tx += TX_RING_SIZE;
 629                         }
 630 #endif
 631
 632                         if (tp->cur_tx - dirty_tx < TX_RING_SIZE - 2)
 633                                 netif_wake_queue(dev);
 634
 635                         tp->dirty_tx = dirty_tx;
 636                         if (csr5 & TxDied) {
 637                                 if (tulip_debug > 2)
 638                                         printk(KERN_WARNING "%s: The transmitter stopped."
 639                                                    "  CSR5 is %x, CSR6 %x, new CSR6 %x.\n",
 640                                                    dev->name, csr5, ioread32(ioaddr + CSR6), tp->csr6);
 641                                 tulip_restart_rxtx(tp);
 642                         }
 643                         spin_unlock(&tp->lock);
 644                 }
 645
 646                 /* Log errors. */
 647                 if (csr5 & AbnormalIntr) {      /* Abnormal error summary bit. */
 648                         if (csr5 == 0xffffffff)
 649                                 break;
 650                         if (csr5 & TxJabber) tp->stats.tx_errors++;
 651                         if (csr5 & TxFIFOUnderflow) {
 652                                 if ((tp->csr6 & 0xC000) != 0xC000)
 653                                         tp->csr6 += 0x4000;     /* Bump up the Tx threshold */
 654                                 else
 655                                         tp->csr6 |= 0x00200000;  /* Store-n-forward. */
 656                                 /* Restart the transmit process. */
 657                                 tulip_restart_rxtx(tp);
 658                                 iowrite32(0, ioaddr + CSR1);
 659                         }
 660                         if (csr5 & (RxDied | RxNoBuf)) {
 661                                 if (tp->flags & COMET_MAC_ADDR) {
 662                                         iowrite32(tp->mc_filter[0], ioaddr + 0xAC);
 663                                         iowrite32(tp->mc_filter[1], ioaddr + 0xB0);
 664                                 }
 665                         }
 666                         if (csr5 & RxDied) {            /* Missed a Rx frame. */
 667                                 tp->stats.rx_missed_errors += ioread32(ioaddr + CSR8) & 0xffff;
 668                                 tp->stats.rx_errors++;
 669                                 tulip_start_rxtx(tp);
 670                         }
 671                         /*
 672                          * NB: t21142_lnk_change() does a del_timer_sync(), so be careful if this
 673                          * call is ever done under the spinlock
 674                          */
 675                         if (csr5 & (TPLnkPass | TPLnkFail | 0x08000000)) {
 676                                 if (tp->link_change)
 677                                         (tp->link_change)(dev, csr5);
 678                         }
 679                         if (csr5 & SytemError) {
 680                                 int error = (csr5 >> 23) & 7;
 681                                 /* oops, we hit a PCI error.  The code produced corresponds
 682                                  * to the reason:
 683                                  *  0 - parity error
 684                                  *  1 - master abort
 685                                  *  2 - target abort
 686                                  * Note that on parity error, we should do a software reset
 687                                  * of the chip to get it back into a sane state (according
 688                                  * to the 21142/3 docs that is).
 689                                  *   -- rmk
 690                                  */
 691                                 printk(KERN_ERR "%s: (%lu) System Error occurred (%d)\n",
 692                                         dev->name, tp->nir, error);
 693                         }
 694                         /* Clear all error sources, included undocumented ones! */
 695                         iowrite32(0x0800f7ba, ioaddr + CSR5);
 696                         oi++;
 697                 }
 698                 if (csr5 & TimerInt) {
 699
 700                         if (tulip_debug > 2)
 701                                 printk(KERN_ERR "%s: Re-enabling interrupts, %8.8x.\n",
 702                                            dev->name, csr5);
 703                         iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ioaddr + CSR7);
 704                         tp->ttimer = 0;
 705                         oi++;
 706                 }
 707                 if (tx > maxtx || rx > maxrx || oi > maxoi) {
 708                         if (tulip_debug > 1)
 709                                 printk(KERN_WARNING "%s: Too much work during an interrupt, "
 710                                            "csr5=0x%8.8x. (%lu) (%d,%d,%d)\n", dev->name, csr5, tp->nir, tx, rx, oi);
 711
 712                        /* Acknowledge all interrupt sources. */
 713                         iowrite32(0x8001ffff, ioaddr + CSR5);
 714                         if (tp->flags & HAS_INTR_MITIGATION) {
 715                      /* Josip Loncaric at ICASE did extensive experimentation
 716                         to develop a good interrupt mitigation setting.*/
 717                                 iowrite32(0x8b240000, ioaddr + CSR11);
 718                         } else if (tp->chip_id == LC82C168) {
 719                                 /* the LC82C168 doesn't have a hw timer.*/
 720                                 iowrite32(0x00, ioaddr + CSR7);
 721                                 mod_timer(&tp->timer, RUN_AT(HZ/50));
 722                         } else {
 723                           /* Mask all interrupting sources, set timer to
 724                                 re-enable. */
 725                                 iowrite32(((~csr5) & 0x0001ebef) | AbnormalIntr | TimerInt, ioaddr + CSR7);
 726                                 iowrite32(0x0012, ioaddr + CSR11);
 727                         }
 728                         break;
 729                 }
 730
 731                 work_count--;
 732                 if (work_count == 0)
 733                         break;
 734
 735                 csr5 = ioread32(ioaddr + CSR5);
 736
 737 #ifdef CONFIG_TULIP_NAPI
 738                 if (rxd)
 739                         csr5 &= ~RxPollInt;
 740         } while ((csr5 & (TxNoBuf |
 741                           TxDied |
 742                           TxIntr |
 743                           TimerInt |
 744                           /* Abnormal intr. */
 745                           RxDied |
 746                           TxFIFOUnderflow |
 747                           TxJabber |
 748                           TPLnkFail |
 749                           SytemError )) != 0);
 750 #else
 751         } while ((csr5 & (NormalIntr|AbnormalIntr)) != 0);
 752
 753         tulip_refill_rx(dev);
 754
 755         /* check if the card is in suspend mode */
 756         entry = tp->dirty_rx % RX_RING_SIZE;
 757         if (tp->rx_buffers[entry].skb == NULL) {
 758                 if (tulip_debug > 1)
 759                         printk(KERN_WARNING "%s: in rx suspend mode: (%lu) (tp->cur_rx = %u, ttimer = %d, rx = %d) go/stay in suspend mode\n", dev->name, tp->nir, tp->cur_rx, tp->ttimer, rx);
 760                 if (tp->chip_id == LC82C168) {
 761                         iowrite32(0x00, ioaddr + CSR7);
 762                         mod_timer(&tp->timer, RUN_AT(HZ/50));
 763                 } else {
 764                         if (tp->ttimer == 0 || (ioread32(ioaddr + CSR11) & 0xffff) == 0) {
 765                                 if (tulip_debug > 1)
 766                                         printk(KERN_WARNING "%s: in rx suspend mode: (%lu) set timer\n", dev->name, tp->nir);
 767                                 iowrite32(tulip_tbl[tp->chip_id].valid_intrs | TimerInt,
 768                                         ioaddr + CSR7);
 769                                 iowrite32(TimerInt, ioaddr + CSR5);
 770                                 iowrite32(12, ioaddr + CSR11);
 771                                 tp->ttimer = 1;
 772                         }
 773                 }
 774         }
 775 #endif /* CONFIG_TULIP_NAPI */
 776
 777         if ((missed = ioread32(ioaddr + CSR8) & 0x1ffff)) {
 778                 tp->stats.rx_dropped += missed & 0x10000 ? 0x10000 : missed;
 779         }
 780
 781         if (tulip_debug > 4)
 782                 printk(KERN_DEBUG "%s: exiting interrupt, csr5=%#4.4x.\n",
 783                            dev->name, ioread32(ioaddr + CSR5));
 784
 785         return IRQ_HANDLED;
 786 }