drivers/ide/ide-atapi.c

   1 /*
   2  * ATAPI support.
   3  */
   4
   5 #include <linux/kernel.h>
   6 #include <linux/cdrom.h>
   7 #include <linux/delay.h>
   8 #include <linux/export.h>
   9 #include <linux/ide.h>
  10 #include <linux/scatterlist.h>
  11 #include <linux/gfp.h>
  12
  13 #include <scsi/scsi.h>
  14
  15 #define DRV_NAME "ide-atapi"
  16 #define PFX DRV_NAME ": "
  17
  18 #ifdef DEBUG
  19 #define debug_log(fmt, args...) \
  20         printk(KERN_INFO "ide: " fmt, ## args)
  21 #else
  22 #define debug_log(fmt, args...) do {} while (0)
  23 #endif
  24
  25 #define ATAPI_MIN_CDB_BYTES     12
  26
  27 static inline int dev_is_idecd(ide_drive_t *drive)
  28 {
  29         return drive->media == ide_cdrom || drive->media == ide_optical;
  30 }
  31
  32 /*
  33  * Check whether we can support a device,
  34  * based on the ATAPI IDENTIFY command results.
  35  */
  36 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
  37 {
  38         u16 *id = drive->id;
  39         u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
  40
  41         *((u16 *)&gcw) = id[ATA_ID_CONFIG];
  42
  43         protocol    = (gcw[1] & 0xC0) >> 6;
  44         device_type =  gcw[1] & 0x1F;
  45         removable   = (gcw[0] & 0x80) >> 7;
  46         drq_type    = (gcw[0] & 0x60) >> 5;
  47         packet_size =  gcw[0] & 0x03;
  48
  49 #ifdef CONFIG_PPC
  50         /* kludge for Apple PowerBook internal zip */
  51         if (drive->media == ide_floppy && device_type == 5 &&
  52             !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
  53             strstr((char *)&id[ATA_ID_PROD], "ZIP"))
  54                 device_type = 0;
  55 #endif
  56
  57         if (protocol != 2)
  58                 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
  59                         s, drive->name, protocol);
  60         else if ((drive->media == ide_floppy && device_type != 0) ||
  61                  (drive->media == ide_tape && device_type != 1))
  62                 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
  63                         s, drive->name, device_type);
  64         else if (removable == 0)
  65                 printk(KERN_ERR "%s: %s: the removable flag is not set\n",
  66                         s, drive->name);
  67         else if (drive->media == ide_floppy && drq_type == 3)
  68                 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
  69                         "supported\n", s, drive->name, drq_type);
  70         else if (packet_size != 0)
  71                 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
  72                         "bytes\n", s, drive->name, packet_size);
  73         else
  74                 return 1;
  75         return 0;
  76 }
  77 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
  78
  79 void ide_init_pc(struct ide_atapi_pc *pc)
  80 {
  81         memset(pc, 0, sizeof(*pc));
  82 }
  83 EXPORT_SYMBOL_GPL(ide_init_pc);
  84
  85 /*
  86  * Add a special packet command request to the tail of the request queue,
  87  * and wait for it to be serviced.
  88  */
  89 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
  90                       struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
  91 {
  92         struct request *rq;
  93         int error;
  94
  95         rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
  96         scsi_req_init(rq);
  97         ide_req(rq)->type = ATA_PRIV_MISC;
  98         rq->special = (char *)pc;
  99
 100         if (buf && bufflen) {
 101                 error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
 102                                         GFP_NOIO);
 103                 if (error)
 104                         goto put_req;
 105         }
 106
 107         memcpy(scsi_req(rq)->cmd, pc->c, 12);
 108         if (drive->media == ide_tape)
 109                 scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
 110         error = blk_execute_rq(drive->queue, disk, rq, 0);
 111 put_req:
 112         blk_put_request(rq);
 113         return error;
 114 }
 115 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
 116
 117 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
 118 {
 119         struct ide_atapi_pc pc;
 120
 121         ide_init_pc(&pc);
 122         pc.c[0] = TEST_UNIT_READY;
 123
 124         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 125 }
 126 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
 127
 128 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
 129 {
 130         struct ide_atapi_pc pc;
 131
 132         ide_init_pc(&pc);
 133         pc.c[0] = START_STOP;
 134         pc.c[4] = start;
 135
 136         if (drive->media == ide_tape)
 137                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
 138
 139         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 140 }
 141 EXPORT_SYMBOL_GPL(ide_do_start_stop);
 142
 143 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
 144 {
 145         struct ide_atapi_pc pc;
 146
 147         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
 148                 return 0;
 149
 150         ide_init_pc(&pc);
 151         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
 152         pc.c[4] = on;
 153
 154         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 155 }
 156 EXPORT_SYMBOL_GPL(ide_set_media_lock);
 157
 158 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
 159 {
 160         ide_init_pc(pc);
 161         pc->c[0] = REQUEST_SENSE;
 162         if (drive->media == ide_floppy) {
 163                 pc->c[4] = 255;
 164                 pc->req_xfer = 18;
 165         } else {
 166                 pc->c[4] = 20;
 167                 pc->req_xfer = 20;
 168         }
 169 }
 170 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
 171
 172 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
 173 {
 174         struct request_sense *sense = &drive->sense_data;
 175         struct request *sense_rq = drive->sense_rq;
 176         struct scsi_request *req = scsi_req(sense_rq);
 177         unsigned int cmd_len, sense_len;
 178         int err;
 179
 180         switch (drive->media) {
 181         case ide_floppy:
 182                 cmd_len = 255;
 183                 sense_len = 18;
 184                 break;
 185         case ide_tape:
 186                 cmd_len = 20;
 187                 sense_len = 20;
 188                 break;
 189         default:
 190                 cmd_len = 18;
 191                 sense_len = 18;
 192         }
 193
 194         BUG_ON(sense_len > sizeof(*sense));
 195
 196         if (ata_sense_request(rq) || drive->sense_rq_armed)
 197                 return;
 198
 199         memset(sense, 0, sizeof(*sense));
 200
 201         blk_rq_init(rq->q, sense_rq);
 202         scsi_req_init(sense_rq);
 203
 204         err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
 205                               GFP_NOIO);
 206         if (unlikely(err)) {
 207                 if (printk_ratelimit())
 208                         printk(KERN_WARNING PFX "%s: failed to map sense "
 209                                             "buffer\n", drive->name);
 210                 return;
 211         }
 212
 213         sense_rq->rq_disk = rq->rq_disk;
 214         sense_rq->cmd_flags = REQ_OP_DRV_IN;
 215         ide_req(sense_rq)->type = ATA_PRIV_SENSE;
 216         sense_rq->rq_flags |= RQF_PREEMPT;
 217
 218         req->cmd[0] = GPCMD_REQUEST_SENSE;
 219         req->cmd[4] = cmd_len;
 220         if (drive->media == ide_tape)
 221                 req->cmd[13] = REQ_IDETAPE_PC1;
 222
 223         drive->sense_rq_armed = true;
 224 }
 225 EXPORT_SYMBOL_GPL(ide_prep_sense);
 226
 227 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
 228 {
 229         /* deferred failure from ide_prep_sense() */
 230         if (!drive->sense_rq_armed) {
 231                 printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
 232                        drive->name);
 233                 return -ENOMEM;
 234         }
 235
 236         drive->sense_rq->special = special;
 237         drive->sense_rq_armed = false;
 238
 239         drive->hwif->rq = NULL;
 240
 241         elv_add_request(drive->queue, drive->sense_rq, ELEVATOR_INSERT_FRONT);
 242         return 0;
 243 }
 244 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
 245
 246 /*
 247  * Called when an error was detected during the last packet command.
 248  * We queue a request sense packet command at the head of the request
 249  * queue.
 250  */
 251 void ide_retry_pc(ide_drive_t *drive)
 252 {
 253         struct request *failed_rq = drive->hwif->rq;
 254         struct request *sense_rq = drive->sense_rq;
 255         struct ide_atapi_pc *pc = &drive->request_sense_pc;
 256
 257         (void)ide_read_error(drive);
 258
 259         /* init pc from sense_rq */
 260         ide_init_pc(pc);
 261         memcpy(pc->c, scsi_req(sense_rq)->cmd, 12);
 262
 263         if (drive->media == ide_tape)
 264                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 265
 266         /*
 267          * Push back the failed request and put request sense on top
 268          * of it.  The failed command will be retried after sense data
 269          * is acquired.
 270          */
 271         drive->hwif->rq = NULL;
 272         ide_requeue_and_plug(drive, failed_rq);
 273         if (ide_queue_sense_rq(drive, pc)) {
 274                 blk_start_request(failed_rq);
 275                 ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
 276         }
 277 }
 278 EXPORT_SYMBOL_GPL(ide_retry_pc);
 279
 280 int ide_cd_expiry(ide_drive_t *drive)
 281 {
 282         struct request *rq = drive->hwif->rq;
 283         unsigned long wait = 0;
 284
 285         debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
 286
 287         /*
 288          * Some commands are *slow* and normally take a long time to complete.
 289          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
 290          * commands/drives support that. Let ide_timer_expiry keep polling us
 291          * for these.
 292          */
 293         switch (scsi_req(rq)->cmd[0]) {
 294         case GPCMD_BLANK:
 295         case GPCMD_FORMAT_UNIT:
 296         case GPCMD_RESERVE_RZONE_TRACK:
 297         case GPCMD_CLOSE_TRACK:
 298         case GPCMD_FLUSH_CACHE:
 299                 wait = ATAPI_WAIT_PC;
 300                 break;
 301         default:
 302                 if (!(rq->rq_flags & RQF_QUIET))
 303                         printk(KERN_INFO PFX "cmd 0x%x timed out\n",
 304                                          scsi_req(rq)->cmd[0]);
 305                 wait = 0;
 306                 break;
 307         }
 308         return wait;
 309 }
 310 EXPORT_SYMBOL_GPL(ide_cd_expiry);
 311
 312 int ide_cd_get_xferlen(struct request *rq)
 313 {
 314         switch (req_op(rq)) {
 315         default:
 316                 return 32768;
 317         case REQ_OP_SCSI_IN:
 318         case REQ_OP_SCSI_OUT:
 319                 return blk_rq_bytes(rq);
 320         case REQ_OP_DRV_IN:
 321         case REQ_OP_DRV_OUT:
 322                 switch (ide_req(rq)->type) {
 323                 case ATA_PRIV_PC:
 324                 case ATA_PRIV_SENSE:
 325                         return blk_rq_bytes(rq);
 326                 default:
 327                         return 0;
 328                 }
 329         }
 330 }
 331 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
 332
 333 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
 334 {
 335         struct ide_taskfile tf;
 336
 337         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
 338                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
 339
 340         *bcount = (tf.lbah << 8) | tf.lbam;
 341         *ireason = tf.nsect & 3;
 342 }
 343 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
 344
 345 /*
 346  * Check the contents of the interrupt reason register and attempt to recover if
 347  * there are problems.
 348  *
 349  * Returns:
 350  * - 0 if everything's ok
 351  * - 1 if the request has to be terminated.
 352  */
 353 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
 354                       int ireason, int rw)
 355 {
 356         ide_hwif_t *hwif = drive->hwif;
 357
 358         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
 359
 360         if (ireason == (!rw << 1))
 361                 return 0;
 362         else if (ireason == (rw << 1)) {
 363                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
 364                                 drive->name, __func__);
 365
 366                 if (dev_is_idecd(drive))
 367                         ide_pad_transfer(drive, rw, len);
 368         } else if (!rw && ireason == ATAPI_COD) {
 369                 if (dev_is_idecd(drive)) {
 370                         /*
 371                          * Some drives (ASUS) seem to tell us that status info
 372                          * is available.  Just get it and ignore.
 373                          */
 374                         (void)hwif->tp_ops->read_status(hwif);
 375                         return 0;
 376                 }
 377         } else {
 378                 if (ireason & ATAPI_COD)
 379                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
 380                                         __func__);
 381
 382                 /* drive wants a command packet, or invalid ireason... */
 383                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
 384                                 drive->name, __func__, ireason);
 385         }
 386
 387         if (dev_is_idecd(drive) && ata_pc_request(rq))
 388                 rq->rq_flags |= RQF_FAILED;
 389
 390         return 1;
 391 }
 392 EXPORT_SYMBOL_GPL(ide_check_ireason);
 393
 394 /*
 395  * This is the usual interrupt handler which will be called during a packet
 396  * command.  We will transfer some of the data (as requested by the drive)
 397  * and will re-point interrupt handler to us.
 398  */
 399 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 400 {
 401         struct ide_atapi_pc *pc = drive->pc;
 402         ide_hwif_t *hwif = drive->hwif;
 403         struct ide_cmd *cmd = &hwif->cmd;
 404         struct request *rq = hwif->rq;
 405         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 406         unsigned int timeout, done;
 407         u16 bcount;
 408         u8 stat, ireason, dsc = 0;
 409         u8 write = !!(pc->flags & PC_FLAG_WRITING);
 410
 411         debug_log("Enter %s - interrupt handler\n", __func__);
 412
 413         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 414                                                : WAIT_TAPE_CMD;
 415
 416         /* Clear the interrupt */
 417         stat = tp_ops->read_status(hwif);
 418
 419         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 420                 int rc;
 421
 422                 drive->waiting_for_dma = 0;
 423                 rc = hwif->dma_ops->dma_end(drive);
 424                 ide_dma_unmap_sg(drive, cmd);
 425
 426                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
 427                         if (drive->media == ide_floppy)
 428                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
 429                                         drive->name, rq_data_dir(pc->rq)
 430                                                      ? "write" : "read");
 431                         pc->flags |= PC_FLAG_DMA_ERROR;
 432                 } else
 433                         scsi_req(rq)->resid_len = 0;
 434                 debug_log("%s: DMA finished\n", drive->name);
 435         }
 436
 437         /* No more interrupts */
 438         if ((stat & ATA_DRQ) == 0) {
 439                 int uptodate, error;
 440
 441                 debug_log("Packet command completed, %d bytes transferred\n",
 442                           blk_rq_bytes(rq));
 443
 444                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 445
 446                 local_irq_enable_in_hardirq();
 447
 448                 if (drive->media == ide_tape &&
 449                     (stat & ATA_ERR) && scsi_req(rq)->cmd[0] == REQUEST_SENSE)
 450                         stat &= ~ATA_ERR;
 451
 452                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
 453                         /* Error detected */
 454                         debug_log("%s: I/O error\n", drive->name);
 455
 456                         if (drive->media != ide_tape)
 457                                 pc->rq->errors++;
 458
 459                         if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
 460                                 printk(KERN_ERR PFX "%s: I/O error in request "
 461                                                 "sense command\n", drive->name);
 462                                 return ide_do_reset(drive);
 463                         }
 464
 465                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
 466
 467                         /* Retry operation */
 468                         ide_retry_pc(drive);
 469
 470                         /* queued, but not started */
 471                         return ide_stopped;
 472                 }
 473                 pc->error = 0;
 474
 475                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
 476                         dsc = 1;
 477
 478                 /*
 479                  * ->pc_callback() might change rq->data_len for
 480                  * residual count, cache total length.
 481                  */
 482                 done = blk_rq_bytes(rq);
 483
 484                 /* Command finished - Call the callback function */
 485                 uptodate = drive->pc_callback(drive, dsc);
 486
 487                 if (uptodate == 0)
 488                         drive->failed_pc = NULL;
 489
 490                 if (ata_misc_request(rq)) {
 491                         rq->errors = 0;
 492                         error = 0;
 493                 } else {
 494
 495                         if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
 496                                 if (rq->errors == 0)
 497                                         rq->errors = -EIO;
 498                         }
 499
 500                         error = uptodate ? 0 : -EIO;
 501                 }
 502
 503                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
 504                 return ide_stopped;
 505         }
 506
 507         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 508                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 509                 printk(KERN_ERR PFX "%s: The device wants to issue more "
 510                                 "interrupts in DMA mode\n", drive->name);
 511                 ide_dma_off(drive);
 512                 return ide_do_reset(drive);
 513         }
 514
 515         /* Get the number of bytes to transfer on this interrupt. */
 516         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
 517
 518         if (ide_check_ireason(drive, rq, bcount, ireason, write))
 519                 return ide_do_reset(drive);
 520
 521         done = min_t(unsigned int, bcount, cmd->nleft);
 522         ide_pio_bytes(drive, cmd, write, done);
 523
 524         /* Update transferred byte count */
 525         scsi_req(rq)->resid_len -= done;
 526
 527         bcount -= done;
 528
 529         if (bcount)
 530                 ide_pad_transfer(drive, write, bcount);
 531
 532         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
 533                   rq->cmd[0], done, bcount, scsi_req(rq)->resid_len);
 534
 535         /* And set the interrupt handler again */
 536         ide_set_handler(drive, ide_pc_intr, timeout);
 537         return ide_started;
 538 }
 539
 540 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
 541                                 u16 bcount, u8 dma)
 542 {
 543         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
 544         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
 545                             IDE_VALID_FEATURE | valid_tf;
 546         cmd->tf.command = ATA_CMD_PACKET;
 547         cmd->tf.feature = dma;          /* Use PIO/DMA */
 548         cmd->tf.lbam    = bcount & 0xff;
 549         cmd->tf.lbah    = (bcount >> 8) & 0xff;
 550 }
 551
 552 static u8 ide_read_ireason(ide_drive_t *drive)
 553 {
 554         struct ide_taskfile tf;
 555
 556         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
 557
 558         return tf.nsect & 3;
 559 }
 560
 561 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
 562 {
 563         int retries = 100;
 564
 565         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
 566                 (ireason & ATAPI_IO))) {
 567                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
 568                                 "a packet command, retrying\n", drive->name);
 569                 udelay(100);
 570                 ireason = ide_read_ireason(drive);
 571                 if (retries == 0) {
 572                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
 573                                         " a packet command, ignoring\n",
 574                                         drive->name);
 575                         ireason |= ATAPI_COD;
 576                         ireason &= ~ATAPI_IO;
 577                 }
 578         }
 579
 580         return ireason;
 581 }
 582
 583 static int ide_delayed_transfer_pc(ide_drive_t *drive)
 584 {
 585         /* Send the actual packet */
 586         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
 587
 588         /* Timeout for the packet command */
 589         return WAIT_FLOPPY_CMD;
 590 }
 591
 592 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 593 {
 594         struct ide_atapi_pc *uninitialized_var(pc);
 595         ide_hwif_t *hwif = drive->hwif;
 596         struct request *rq = hwif->rq;
 597         ide_expiry_t *expiry;
 598         unsigned int timeout;
 599         int cmd_len;
 600         ide_startstop_t startstop;
 601         u8 ireason;
 602
 603         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
 604                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
 605                                 "DRQ isn't asserted\n", drive->name);
 606                 return startstop;
 607         }
 608
 609         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 610                 if (drive->dma)
 611                         drive->waiting_for_dma = 1;
 612         }
 613
 614         if (dev_is_idecd(drive)) {
 615                 /* ATAPI commands get padded out to 12 bytes minimum */
 616                 cmd_len = COMMAND_SIZE(scsi_req(rq)->cmd[0]);
 617                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
 618                         cmd_len = ATAPI_MIN_CDB_BYTES;
 619
 620                 timeout = rq->timeout;
 621                 expiry  = ide_cd_expiry;
 622         } else {
 623                 pc = drive->pc;
 624
 625                 cmd_len = ATAPI_MIN_CDB_BYTES;
 626
 627                 /*
 628                  * If necessary schedule the packet transfer to occur 'timeout'
 629                  * milliseconds later in ide_delayed_transfer_pc() after the
 630                  * device says it's ready for a packet.
 631                  */
 632                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
 633                         timeout = drive->pc_delay;
 634                         expiry = &ide_delayed_transfer_pc;
 635                 } else {
 636                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 637                                                                : WAIT_TAPE_CMD;
 638                         expiry = NULL;
 639                 }
 640
 641                 ireason = ide_read_ireason(drive);
 642                 if (drive->media == ide_tape)
 643                         ireason = ide_wait_ireason(drive, ireason);
 644
 645                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
 646                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
 647                                 "issuing a packet command\n", drive->name);
 648
 649                         return ide_do_reset(drive);
 650                 }
 651         }
 652
 653         hwif->expiry = expiry;
 654
 655         /* Set the interrupt routine */
 656         ide_set_handler(drive,
 657                         (dev_is_idecd(drive) ? drive->irq_handler
 658                                              : ide_pc_intr),
 659                         timeout);
 660
 661         /* Send the actual packet */
 662         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
 663                 hwif->tp_ops->output_data(drive, NULL, scsi_req(rq)->cmd, cmd_len);
 664
 665         /* Begin DMA, if necessary */
 666         if (dev_is_idecd(drive)) {
 667                 if (drive->dma)
 668                         hwif->dma_ops->dma_start(drive);
 669         } else {
 670                 if (pc->flags & PC_FLAG_DMA_OK) {
 671                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
 672                         hwif->dma_ops->dma_start(drive);
 673                 }
 674         }
 675
 676         return ide_started;
 677 }
 678
 679 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 680 {
 681         struct ide_atapi_pc *pc;
 682         ide_hwif_t *hwif = drive->hwif;
 683         ide_expiry_t *expiry = NULL;
 684         struct request *rq = hwif->rq;
 685         unsigned int timeout, bytes;
 686         u16 bcount;
 687         u8 valid_tf;
 688         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
 689
 690         if (dev_is_idecd(drive)) {
 691                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
 692                 bcount = ide_cd_get_xferlen(rq);
 693                 expiry = ide_cd_expiry;
 694                 timeout = ATAPI_WAIT_PC;
 695
 696                 if (drive->dma)
 697                         drive->dma = !ide_dma_prepare(drive, cmd);
 698         } else {
 699                 pc = drive->pc;
 700
 701                 valid_tf = IDE_VALID_DEVICE;
 702                 bytes = blk_rq_bytes(rq);
 703                 bcount = ((drive->media == ide_tape) ? bytes
 704                                                      : min_t(unsigned int,
 705                                                              bytes, 63 * 1024));
 706
 707                 /* We haven't transferred any data yet */
 708                 scsi_req(rq)->resid_len = bcount;
 709
 710                 if (pc->flags & PC_FLAG_DMA_ERROR) {
 711                         pc->flags &= ~PC_FLAG_DMA_ERROR;
 712                         ide_dma_off(drive);
 713                 }
 714
 715                 if (pc->flags & PC_FLAG_DMA_OK)
 716                         drive->dma = !ide_dma_prepare(drive, cmd);
 717
 718                 if (!drive->dma)
 719                         pc->flags &= ~PC_FLAG_DMA_OK;
 720
 721                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 722                                                        : WAIT_TAPE_CMD;
 723         }
 724
 725         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
 726
 727         (void)do_rw_taskfile(drive, cmd);
 728
 729         if (drq_int) {
 730                 if (drive->dma)
 731                         drive->waiting_for_dma = 0;
 732                 hwif->expiry = expiry;
 733         }
 734
 735         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
 736
 737         return drq_int ? ide_started : ide_transfer_pc(drive);
 738 }
 739 EXPORT_SYMBOL_GPL(ide_issue_pc);