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         blk_execute_rq(drive->queue, disk, rq, 0);
 111         error = scsi_req(rq)->result ? -EIO : 0;
 112 put_req:
 113         blk_put_request(rq);
 114         return error;
 115 }
 116 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
 117
 118 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
 119 {
 120         struct ide_atapi_pc pc;
 121
 122         ide_init_pc(&pc);
 123         pc.c[0] = TEST_UNIT_READY;
 124
 125         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 126 }
 127 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
 128
 129 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
 130 {
 131         struct ide_atapi_pc pc;
 132
 133         ide_init_pc(&pc);
 134         pc.c[0] = START_STOP;
 135         pc.c[4] = start;
 136
 137         if (drive->media == ide_tape)
 138                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
 139
 140         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 141 }
 142 EXPORT_SYMBOL_GPL(ide_do_start_stop);
 143
 144 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
 145 {
 146         struct ide_atapi_pc pc;
 147
 148         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
 149                 return 0;
 150
 151         ide_init_pc(&pc);
 152         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
 153         pc.c[4] = on;
 154
 155         return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
 156 }
 157 EXPORT_SYMBOL_GPL(ide_set_media_lock);
 158
 159 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
 160 {
 161         ide_init_pc(pc);
 162         pc->c[0] = REQUEST_SENSE;
 163         if (drive->media == ide_floppy) {
 164                 pc->c[4] = 255;
 165                 pc->req_xfer = 18;
 166         } else {
 167                 pc->c[4] = 20;
 168                 pc->req_xfer = 20;
 169         }
 170 }
 171 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
 172
 173 void ide_prep_sense(ide_drive_t *drive, struct request *rq)
 174 {
 175         struct request_sense *sense = &drive->sense_data;
 176         struct request *sense_rq = drive->sense_rq;
 177         struct scsi_request *req = scsi_req(sense_rq);
 178         unsigned int cmd_len, sense_len;
 179         int err;
 180
 181         switch (drive->media) {
 182         case ide_floppy:
 183                 cmd_len = 255;
 184                 sense_len = 18;
 185                 break;
 186         case ide_tape:
 187                 cmd_len = 20;
 188                 sense_len = 20;
 189                 break;
 190         default:
 191                 cmd_len = 18;
 192                 sense_len = 18;
 193         }
 194
 195         BUG_ON(sense_len > sizeof(*sense));
 196
 197         if (ata_sense_request(rq) || drive->sense_rq_armed)
 198                 return;
 199
 200         memset(sense, 0, sizeof(*sense));
 201
 202         blk_rq_init(rq->q, sense_rq);
 203         scsi_req_init(sense_rq);
 204
 205         err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
 206                               GFP_NOIO);
 207         if (unlikely(err)) {
 208                 if (printk_ratelimit())
 209                         printk(KERN_WARNING PFX "%s: failed to map sense "
 210                                             "buffer\n", drive->name);
 211                 return;
 212         }
 213
 214         sense_rq->rq_disk = rq->rq_disk;
 215         sense_rq->cmd_flags = REQ_OP_DRV_IN;
 216         ide_req(sense_rq)->type = ATA_PRIV_SENSE;
 217         sense_rq->rq_flags |= RQF_PREEMPT;
 218
 219         req->cmd[0] = GPCMD_REQUEST_SENSE;
 220         req->cmd[4] = cmd_len;
 221         if (drive->media == ide_tape)
 222                 req->cmd[13] = REQ_IDETAPE_PC1;
 223
 224         drive->sense_rq_armed = true;
 225 }
 226 EXPORT_SYMBOL_GPL(ide_prep_sense);
 227
 228 int ide_queue_sense_rq(ide_drive_t *drive, void *special)
 229 {
 230         /* deferred failure from ide_prep_sense() */
 231         if (!drive->sense_rq_armed) {
 232                 printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
 233                        drive->name);
 234                 return -ENOMEM;
 235         }
 236
 237         drive->sense_rq->special = special;
 238         drive->sense_rq_armed = false;
 239
 240         drive->hwif->rq = NULL;
 241
 242         elv_add_request(drive->queue, drive->sense_rq, ELEVATOR_INSERT_FRONT);
 243         return 0;
 244 }
 245 EXPORT_SYMBOL_GPL(ide_queue_sense_rq);
 246
 247 /*
 248  * Called when an error was detected during the last packet command.
 249  * We queue a request sense packet command at the head of the request
 250  * queue.
 251  */
 252 void ide_retry_pc(ide_drive_t *drive)
 253 {
 254         struct request *failed_rq = drive->hwif->rq;
 255         struct request *sense_rq = drive->sense_rq;
 256         struct ide_atapi_pc *pc = &drive->request_sense_pc;
 257
 258         (void)ide_read_error(drive);
 259
 260         /* init pc from sense_rq */
 261         ide_init_pc(pc);
 262         memcpy(pc->c, scsi_req(sense_rq)->cmd, 12);
 263
 264         if (drive->media == ide_tape)
 265                 drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;
 266
 267         /*
 268          * Push back the failed request and put request sense on top
 269          * of it.  The failed command will be retried after sense data
 270          * is acquired.
 271          */
 272         drive->hwif->rq = NULL;
 273         ide_requeue_and_plug(drive, failed_rq);
 274         if (ide_queue_sense_rq(drive, pc)) {
 275                 blk_start_request(failed_rq);
 276                 ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(failed_rq));
 277         }
 278 }
 279 EXPORT_SYMBOL_GPL(ide_retry_pc);
 280
 281 int ide_cd_expiry(ide_drive_t *drive)
 282 {
 283         struct request *rq = drive->hwif->rq;
 284         unsigned long wait = 0;
 285
 286         debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
 287
 288         /*
 289          * Some commands are *slow* and normally take a long time to complete.
 290          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
 291          * commands/drives support that. Let ide_timer_expiry keep polling us
 292          * for these.
 293          */
 294         switch (scsi_req(rq)->cmd[0]) {
 295         case GPCMD_BLANK:
 296         case GPCMD_FORMAT_UNIT:
 297         case GPCMD_RESERVE_RZONE_TRACK:
 298         case GPCMD_CLOSE_TRACK:
 299         case GPCMD_FLUSH_CACHE:
 300                 wait = ATAPI_WAIT_PC;
 301                 break;
 302         default:
 303                 if (!(rq->rq_flags & RQF_QUIET))
 304                         printk(KERN_INFO PFX "cmd 0x%x timed out\n",
 305                                          scsi_req(rq)->cmd[0]);
 306                 wait = 0;
 307                 break;
 308         }
 309         return wait;
 310 }
 311 EXPORT_SYMBOL_GPL(ide_cd_expiry);
 312
 313 int ide_cd_get_xferlen(struct request *rq)
 314 {
 315         switch (req_op(rq)) {
 316         default:
 317                 return 32768;
 318         case REQ_OP_SCSI_IN:
 319         case REQ_OP_SCSI_OUT:
 320                 return blk_rq_bytes(rq);
 321         case REQ_OP_DRV_IN:
 322         case REQ_OP_DRV_OUT:
 323                 switch (ide_req(rq)->type) {
 324                 case ATA_PRIV_PC:
 325                 case ATA_PRIV_SENSE:
 326                         return blk_rq_bytes(rq);
 327                 default:
 328                         return 0;
 329                 }
 330         }
 331 }
 332 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
 333
 334 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
 335 {
 336         struct ide_taskfile tf;
 337
 338         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
 339                                      IDE_VALID_LBAM | IDE_VALID_LBAH);
 340
 341         *bcount = (tf.lbah << 8) | tf.lbam;
 342         *ireason = tf.nsect & 3;
 343 }
 344 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
 345
 346 /*
 347  * Check the contents of the interrupt reason register and attempt to recover if
 348  * there are problems.
 349  *
 350  * Returns:
 351  * - 0 if everything's ok
 352  * - 1 if the request has to be terminated.
 353  */
 354 int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
 355                       int ireason, int rw)
 356 {
 357         ide_hwif_t *hwif = drive->hwif;
 358
 359         debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);
 360
 361         if (ireason == (!rw << 1))
 362                 return 0;
 363         else if (ireason == (rw << 1)) {
 364                 printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
 365                                 drive->name, __func__);
 366
 367                 if (dev_is_idecd(drive))
 368                         ide_pad_transfer(drive, rw, len);
 369         } else if (!rw && ireason == ATAPI_COD) {
 370                 if (dev_is_idecd(drive)) {
 371                         /*
 372                          * Some drives (ASUS) seem to tell us that status info
 373                          * is available.  Just get it and ignore.
 374                          */
 375                         (void)hwif->tp_ops->read_status(hwif);
 376                         return 0;
 377                 }
 378         } else {
 379                 if (ireason & ATAPI_COD)
 380                         printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
 381                                         __func__);
 382
 383                 /* drive wants a command packet, or invalid ireason... */
 384                 printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
 385                                 drive->name, __func__, ireason);
 386         }
 387
 388         if (dev_is_idecd(drive) && ata_pc_request(rq))
 389                 rq->rq_flags |= RQF_FAILED;
 390
 391         return 1;
 392 }
 393 EXPORT_SYMBOL_GPL(ide_check_ireason);
 394
 395 /*
 396  * This is the usual interrupt handler which will be called during a packet
 397  * command.  We will transfer some of the data (as requested by the drive)
 398  * and will re-point interrupt handler to us.
 399  */
 400 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 401 {
 402         struct ide_atapi_pc *pc = drive->pc;
 403         ide_hwif_t *hwif = drive->hwif;
 404         struct ide_cmd *cmd = &hwif->cmd;
 405         struct request *rq = hwif->rq;
 406         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 407         unsigned int timeout, done;
 408         u16 bcount;
 409         u8 stat, ireason, dsc = 0;
 410         u8 write = !!(pc->flags & PC_FLAG_WRITING);
 411
 412         debug_log("Enter %s - interrupt handler\n", __func__);
 413
 414         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 415                                                : WAIT_TAPE_CMD;
 416
 417         /* Clear the interrupt */
 418         stat = tp_ops->read_status(hwif);
 419
 420         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 421                 int rc;
 422
 423                 drive->waiting_for_dma = 0;
 424                 rc = hwif->dma_ops->dma_end(drive);
 425                 ide_dma_unmap_sg(drive, cmd);
 426
 427                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
 428                         if (drive->media == ide_floppy)
 429                                 printk(KERN_ERR PFX "%s: DMA %s error\n",
 430                                         drive->name, rq_data_dir(pc->rq)
 431                                                      ? "write" : "read");
 432                         pc->flags |= PC_FLAG_DMA_ERROR;
 433                 } else
 434                         scsi_req(rq)->resid_len = 0;
 435                 debug_log("%s: DMA finished\n", drive->name);
 436         }
 437
 438         /* No more interrupts */
 439         if ((stat & ATA_DRQ) == 0) {
 440                 int uptodate;
 441                 blk_status_t error;
 442
 443                 debug_log("Packet command completed, %d bytes transferred\n",
 444                           blk_rq_bytes(rq));
 445
 446                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 447
 448                 local_irq_enable_in_hardirq();
 449
 450                 if (drive->media == ide_tape &&
 451                     (stat & ATA_ERR) && scsi_req(rq)->cmd[0] == REQUEST_SENSE)
 452                         stat &= ~ATA_ERR;
 453
 454                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
 455                         /* Error detected */
 456                         debug_log("%s: I/O error\n", drive->name);
 457
 458                         if (drive->media != ide_tape)
 459                                 scsi_req(pc->rq)->result++;
 460
 461                         if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
 462                                 printk(KERN_ERR PFX "%s: I/O error in request "
 463                                                 "sense command\n", drive->name);
 464                                 return ide_do_reset(drive);
 465                         }
 466
 467                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
 468
 469                         /* Retry operation */
 470                         ide_retry_pc(drive);
 471
 472                         /* queued, but not started */
 473                         return ide_stopped;
 474                 }
 475                 pc->error = 0;
 476
 477                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
 478                         dsc = 1;
 479
 480                 /*
 481                  * ->pc_callback() might change rq->data_len for
 482                  * residual count, cache total length.
 483                  */
 484                 done = blk_rq_bytes(rq);
 485
 486                 /* Command finished - Call the callback function */
 487                 uptodate = drive->pc_callback(drive, dsc);
 488
 489                 if (uptodate == 0)
 490                         drive->failed_pc = NULL;
 491
 492                 if (ata_misc_request(rq)) {
 493                         scsi_req(rq)->result = 0;
 494                         error = BLK_STS_OK;
 495                 } else {
 496
 497                         if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
 498                                 if (scsi_req(rq)->result == 0)
 499                                         scsi_req(rq)->result = -EIO;
 500                         }
 501
 502                         error = uptodate ? BLK_STS_OK : BLK_STS_IOERR;
 503                 }
 504
 505                 ide_complete_rq(drive, error, blk_rq_bytes(rq));
 506                 return ide_stopped;
 507         }
 508
 509         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 510                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 511                 printk(KERN_ERR PFX "%s: The device wants to issue more "
 512                                 "interrupts in DMA mode\n", drive->name);
 513                 ide_dma_off(drive);
 514                 return ide_do_reset(drive);
 515         }
 516
 517         /* Get the number of bytes to transfer on this interrupt. */
 518         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
 519
 520         if (ide_check_ireason(drive, rq, bcount, ireason, write))
 521                 return ide_do_reset(drive);
 522
 523         done = min_t(unsigned int, bcount, cmd->nleft);
 524         ide_pio_bytes(drive, cmd, write, done);
 525
 526         /* Update transferred byte count */
 527         scsi_req(rq)->resid_len -= done;
 528
 529         bcount -= done;
 530
 531         if (bcount)
 532                 ide_pad_transfer(drive, write, bcount);
 533
 534         debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
 535                   rq->cmd[0], done, bcount, scsi_req(rq)->resid_len);
 536
 537         /* And set the interrupt handler again */
 538         ide_set_handler(drive, ide_pc_intr, timeout);
 539         return ide_started;
 540 }
 541
 542 static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
 543                                 u16 bcount, u8 dma)
 544 {
 545         cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
 546         cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
 547                             IDE_VALID_FEATURE | valid_tf;
 548         cmd->tf.command = ATA_CMD_PACKET;
 549         cmd->tf.feature = dma;          /* Use PIO/DMA */
 550         cmd->tf.lbam    = bcount & 0xff;
 551         cmd->tf.lbah    = (bcount >> 8) & 0xff;
 552 }
 553
 554 static u8 ide_read_ireason(ide_drive_t *drive)
 555 {
 556         struct ide_taskfile tf;
 557
 558         drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);
 559
 560         return tf.nsect & 3;
 561 }
 562
 563 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
 564 {
 565         int retries = 100;
 566
 567         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
 568                 (ireason & ATAPI_IO))) {
 569                 printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
 570                                 "a packet command, retrying\n", drive->name);
 571                 udelay(100);
 572                 ireason = ide_read_ireason(drive);
 573                 if (retries == 0) {
 574                         printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
 575                                         " a packet command, ignoring\n",
 576                                         drive->name);
 577                         ireason |= ATAPI_COD;
 578                         ireason &= ~ATAPI_IO;
 579                 }
 580         }
 581
 582         return ireason;
 583 }
 584
 585 static int ide_delayed_transfer_pc(ide_drive_t *drive)
 586 {
 587         /* Send the actual packet */
 588         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
 589
 590         /* Timeout for the packet command */
 591         return WAIT_FLOPPY_CMD;
 592 }
 593
 594 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 595 {
 596         struct ide_atapi_pc *uninitialized_var(pc);
 597         ide_hwif_t *hwif = drive->hwif;
 598         struct request *rq = hwif->rq;
 599         ide_expiry_t *expiry;
 600         unsigned int timeout;
 601         int cmd_len;
 602         ide_startstop_t startstop;
 603         u8 ireason;
 604
 605         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
 606                 printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
 607                                 "DRQ isn't asserted\n", drive->name);
 608                 return startstop;
 609         }
 610
 611         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 612                 if (drive->dma)
 613                         drive->waiting_for_dma = 1;
 614         }
 615
 616         if (dev_is_idecd(drive)) {
 617                 /* ATAPI commands get padded out to 12 bytes minimum */
 618                 cmd_len = COMMAND_SIZE(scsi_req(rq)->cmd[0]);
 619                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
 620                         cmd_len = ATAPI_MIN_CDB_BYTES;
 621
 622                 timeout = rq->timeout;
 623                 expiry  = ide_cd_expiry;
 624         } else {
 625                 pc = drive->pc;
 626
 627                 cmd_len = ATAPI_MIN_CDB_BYTES;
 628
 629                 /*
 630                  * If necessary schedule the packet transfer to occur 'timeout'
 631                  * milliseconds later in ide_delayed_transfer_pc() after the
 632                  * device says it's ready for a packet.
 633                  */
 634                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
 635                         timeout = drive->pc_delay;
 636                         expiry = &ide_delayed_transfer_pc;
 637                 } else {
 638                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 639                                                                : WAIT_TAPE_CMD;
 640                         expiry = NULL;
 641                 }
 642
 643                 ireason = ide_read_ireason(drive);
 644                 if (drive->media == ide_tape)
 645                         ireason = ide_wait_ireason(drive, ireason);
 646
 647                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
 648                         printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
 649                                 "issuing a packet command\n", drive->name);
 650
 651                         return ide_do_reset(drive);
 652                 }
 653         }
 654
 655         hwif->expiry = expiry;
 656
 657         /* Set the interrupt routine */
 658         ide_set_handler(drive,
 659                         (dev_is_idecd(drive) ? drive->irq_handler
 660                                              : ide_pc_intr),
 661                         timeout);
 662
 663         /* Send the actual packet */
 664         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
 665                 hwif->tp_ops->output_data(drive, NULL, scsi_req(rq)->cmd, cmd_len);
 666
 667         /* Begin DMA, if necessary */
 668         if (dev_is_idecd(drive)) {
 669                 if (drive->dma)
 670                         hwif->dma_ops->dma_start(drive);
 671         } else {
 672                 if (pc->flags & PC_FLAG_DMA_OK) {
 673                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
 674                         hwif->dma_ops->dma_start(drive);
 675                 }
 676         }
 677
 678         return ide_started;
 679 }
 680
 681 ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 682 {
 683         struct ide_atapi_pc *pc;
 684         ide_hwif_t *hwif = drive->hwif;
 685         ide_expiry_t *expiry = NULL;
 686         struct request *rq = hwif->rq;
 687         unsigned int timeout, bytes;
 688         u16 bcount;
 689         u8 valid_tf;
 690         u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);
 691
 692         if (dev_is_idecd(drive)) {
 693                 valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
 694                 bcount = ide_cd_get_xferlen(rq);
 695                 expiry = ide_cd_expiry;
 696                 timeout = ATAPI_WAIT_PC;
 697
 698                 if (drive->dma)
 699                         drive->dma = !ide_dma_prepare(drive, cmd);
 700         } else {
 701                 pc = drive->pc;
 702
 703                 valid_tf = IDE_VALID_DEVICE;
 704                 bytes = blk_rq_bytes(rq);
 705                 bcount = ((drive->media == ide_tape) ? bytes
 706                                                      : min_t(unsigned int,
 707                                                              bytes, 63 * 1024));
 708
 709                 /* We haven't transferred any data yet */
 710                 scsi_req(rq)->resid_len = bcount;
 711
 712                 if (pc->flags & PC_FLAG_DMA_ERROR) {
 713                         pc->flags &= ~PC_FLAG_DMA_ERROR;
 714                         ide_dma_off(drive);
 715                 }
 716
 717                 if (pc->flags & PC_FLAG_DMA_OK)
 718                         drive->dma = !ide_dma_prepare(drive, cmd);
 719
 720                 if (!drive->dma)
 721                         pc->flags &= ~PC_FLAG_DMA_OK;
 722
 723                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 724                                                        : WAIT_TAPE_CMD;
 725         }
 726
 727         ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);
 728
 729         (void)do_rw_taskfile(drive, cmd);
 730
 731         if (drq_int) {
 732                 if (drive->dma)
 733                         drive->waiting_for_dma = 0;
 734                 hwif->expiry = expiry;
 735         }
 736
 737         ide_execute_command(drive, cmd, ide_transfer_pc, timeout);
 738
 739         return drq_int ? ide_started : ide_transfer_pc(drive);
 740 }
 741 EXPORT_SYMBOL_GPL(ide_issue_pc);