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