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/ide.h>
   9 #include <scsi/scsi.h>
  10
  11 #ifdef DEBUG
  12 #define debug_log(fmt, args...) \
  13         printk(KERN_INFO "ide: " fmt, ## args)
  14 #else
  15 #define debug_log(fmt, args...) do {} while (0)
  16 #endif
  17
  18 #define ATAPI_MIN_CDB_BYTES     12
  19
  20 static inline int dev_is_idecd(ide_drive_t *drive)
  21 {
  22         return drive->media == ide_cdrom || drive->media == ide_optical;
  23 }
  24
  25 /*
  26  * Check whether we can support a device,
  27  * based on the ATAPI IDENTIFY command results.
  28  */
  29 int ide_check_atapi_device(ide_drive_t *drive, const char *s)
  30 {
  31         u16 *id = drive->id;
  32         u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;
  33
  34         *((u16 *)&gcw) = id[ATA_ID_CONFIG];
  35
  36         protocol    = (gcw[1] & 0xC0) >> 6;
  37         device_type =  gcw[1] & 0x1F;
  38         removable   = (gcw[0] & 0x80) >> 7;
  39         drq_type    = (gcw[0] & 0x60) >> 5;
  40         packet_size =  gcw[0] & 0x03;
  41
  42 #ifdef CONFIG_PPC
  43         /* kludge for Apple PowerBook internal zip */
  44         if (drive->media == ide_floppy && device_type == 5 &&
  45             !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
  46             strstr((char *)&id[ATA_ID_PROD], "ZIP"))
  47                 device_type = 0;
  48 #endif
  49
  50         if (protocol != 2)
  51                 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
  52                         s, drive->name, protocol);
  53         else if ((drive->media == ide_floppy && device_type != 0) ||
  54                  (drive->media == ide_tape && device_type != 1))
  55                 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
  56                         s, drive->name, device_type);
  57         else if (removable == 0)
  58                 printk(KERN_ERR "%s: %s: the removable flag is not set\n",
  59                         s, drive->name);
  60         else if (drive->media == ide_floppy && drq_type == 3)
  61                 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
  62                         "supported\n", s, drive->name, drq_type);
  63         else if (packet_size != 0)
  64                 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
  65                         "bytes\n", s, drive->name, packet_size);
  66         else
  67                 return 1;
  68         return 0;
  69 }
  70 EXPORT_SYMBOL_GPL(ide_check_atapi_device);
  71
  72 /* PIO data transfer routine using the scatter gather table. */
  73 int ide_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
  74                     unsigned int bcount, int write)
  75 {
  76         ide_hwif_t *hwif = drive->hwif;
  77         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
  78         xfer_func_t *xf = write ? tp_ops->output_data : tp_ops->input_data;
  79         struct scatterlist *sg = pc->sg;
  80         char *buf;
  81         int count, done = 0;
  82
  83         while (bcount) {
  84                 count = min(sg->length - pc->b_count, bcount);
  85
  86                 if (PageHighMem(sg_page(sg))) {
  87                         unsigned long flags;
  88
  89                         local_irq_save(flags);
  90                         buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset;
  91                         xf(drive, NULL, buf + pc->b_count, count);
  92                         kunmap_atomic(buf - sg->offset, KM_IRQ0);
  93                         local_irq_restore(flags);
  94                 } else {
  95                         buf = sg_virt(sg);
  96                         xf(drive, NULL, buf + pc->b_count, count);
  97                 }
  98
  99                 bcount -= count;
 100                 pc->b_count += count;
 101                 done += count;
 102
 103                 if (pc->b_count == sg->length) {
 104                         if (!--pc->sg_cnt)
 105                                 break;
 106                         pc->sg = sg = sg_next(sg);
 107                         pc->b_count = 0;
 108                 }
 109         }
 110
 111         if (bcount) {
 112                 printk(KERN_ERR "%s: %d leftover bytes, %s\n", drive->name,
 113                         bcount, write ? "padding with zeros"
 114                                       : "discarding data");
 115                 ide_pad_transfer(drive, write, bcount);
 116         }
 117
 118         return done;
 119 }
 120 EXPORT_SYMBOL_GPL(ide_io_buffers);
 121
 122 void ide_init_pc(struct ide_atapi_pc *pc)
 123 {
 124         memset(pc, 0, sizeof(*pc));
 125         pc->buf = pc->pc_buf;
 126         pc->buf_size = IDE_PC_BUFFER_SIZE;
 127 }
 128 EXPORT_SYMBOL_GPL(ide_init_pc);
 129
 130 /*
 131  * Generate a new packet command request in front of the request queue, before
 132  * the current request, so that it will be processed immediately, on the next
 133  * pass through the driver.
 134  */
 135 static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk,
 136                               struct ide_atapi_pc *pc, struct request *rq)
 137 {
 138         blk_rq_init(NULL, rq);
 139         rq->cmd_type = REQ_TYPE_SPECIAL;
 140         rq->cmd_flags |= REQ_PREEMPT;
 141         rq->buffer = (char *)pc;
 142         rq->rq_disk = disk;
 143
 144         if (pc->req_xfer) {
 145                 rq->data = pc->buf;
 146                 rq->data_len = pc->req_xfer;
 147         }
 148
 149         memcpy(rq->cmd, pc->c, 12);
 150         if (drive->media == ide_tape)
 151                 rq->cmd[13] = REQ_IDETAPE_PC1;
 152
 153         drive->hwif->rq = NULL;
 154
 155         elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0);
 156 }
 157
 158 /*
 159  * Add a special packet command request to the tail of the request queue,
 160  * and wait for it to be serviced.
 161  */
 162 int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 163                       struct ide_atapi_pc *pc)
 164 {
 165         struct request *rq;
 166         int error;
 167
 168         rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
 169         rq->cmd_type = REQ_TYPE_SPECIAL;
 170         rq->buffer = (char *)pc;
 171
 172         if (pc->req_xfer) {
 173                 rq->data = pc->buf;
 174                 rq->data_len = pc->req_xfer;
 175         }
 176
 177         memcpy(rq->cmd, pc->c, 12);
 178         if (drive->media == ide_tape)
 179                 rq->cmd[13] = REQ_IDETAPE_PC1;
 180         error = blk_execute_rq(drive->queue, disk, rq, 0);
 181         blk_put_request(rq);
 182
 183         return error;
 184 }
 185 EXPORT_SYMBOL_GPL(ide_queue_pc_tail);
 186
 187 int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
 188 {
 189         struct ide_atapi_pc pc;
 190
 191         ide_init_pc(&pc);
 192         pc.c[0] = TEST_UNIT_READY;
 193
 194         return ide_queue_pc_tail(drive, disk, &pc);
 195 }
 196 EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);
 197
 198 int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
 199 {
 200         struct ide_atapi_pc pc;
 201
 202         ide_init_pc(&pc);
 203         pc.c[0] = START_STOP;
 204         pc.c[4] = start;
 205
 206         if (drive->media == ide_tape)
 207                 pc.flags |= PC_FLAG_WAIT_FOR_DSC;
 208
 209         return ide_queue_pc_tail(drive, disk, &pc);
 210 }
 211 EXPORT_SYMBOL_GPL(ide_do_start_stop);
 212
 213 int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
 214 {
 215         struct ide_atapi_pc pc;
 216
 217         if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
 218                 return 0;
 219
 220         ide_init_pc(&pc);
 221         pc.c[0] = ALLOW_MEDIUM_REMOVAL;
 222         pc.c[4] = on;
 223
 224         return ide_queue_pc_tail(drive, disk, &pc);
 225 }
 226 EXPORT_SYMBOL_GPL(ide_set_media_lock);
 227
 228 void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
 229 {
 230         ide_init_pc(pc);
 231         pc->c[0] = REQUEST_SENSE;
 232         if (drive->media == ide_floppy) {
 233                 pc->c[4] = 255;
 234                 pc->req_xfer = 18;
 235         } else {
 236                 pc->c[4] = 20;
 237                 pc->req_xfer = 20;
 238         }
 239 }
 240 EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);
 241
 242 /*
 243  * Called when an error was detected during the last packet command.
 244  * We queue a request sense packet command in the head of the request list.
 245  */
 246 void ide_retry_pc(ide_drive_t *drive, struct gendisk *disk)
 247 {
 248         struct request *rq = &drive->request_sense_rq;
 249         struct ide_atapi_pc *pc = &drive->request_sense_pc;
 250
 251         (void)ide_read_error(drive);
 252         ide_create_request_sense_cmd(drive, pc);
 253         if (drive->media == ide_tape)
 254                 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
 255         ide_queue_pc_head(drive, disk, pc, rq);
 256 }
 257 EXPORT_SYMBOL_GPL(ide_retry_pc);
 258
 259 int ide_cd_expiry(ide_drive_t *drive)
 260 {
 261         struct request *rq = drive->hwif->rq;
 262         unsigned long wait = 0;
 263
 264         debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);
 265
 266         /*
 267          * Some commands are *slow* and normally take a long time to complete.
 268          * Usually we can use the ATAPI "disconnect" to bypass this, but not all
 269          * commands/drives support that. Let ide_timer_expiry keep polling us
 270          * for these.
 271          */
 272         switch (rq->cmd[0]) {
 273         case GPCMD_BLANK:
 274         case GPCMD_FORMAT_UNIT:
 275         case GPCMD_RESERVE_RZONE_TRACK:
 276         case GPCMD_CLOSE_TRACK:
 277         case GPCMD_FLUSH_CACHE:
 278                 wait = ATAPI_WAIT_PC;
 279                 break;
 280         default:
 281                 if (!(rq->cmd_flags & REQ_QUIET))
 282                         printk(KERN_INFO "cmd 0x%x timed out\n",
 283                                          rq->cmd[0]);
 284                 wait = 0;
 285                 break;
 286         }
 287         return wait;
 288 }
 289 EXPORT_SYMBOL_GPL(ide_cd_expiry);
 290
 291 int ide_cd_get_xferlen(struct request *rq)
 292 {
 293         if (blk_fs_request(rq))
 294                 return 32768;
 295         else if (blk_sense_request(rq) || blk_pc_request(rq) ||
 296                          rq->cmd_type == REQ_TYPE_ATA_PC)
 297                 return rq->data_len;
 298         else
 299                 return 0;
 300 }
 301 EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);
 302
 303 void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
 304 {
 305         struct ide_cmd cmd;
 306
 307         memset(&cmd, 0, sizeof(cmd));
 308         cmd.tf_flags = IDE_TFLAG_IN_LBAH | IDE_TFLAG_IN_LBAM |
 309                        IDE_TFLAG_IN_NSECT;
 310
 311         drive->hwif->tp_ops->tf_read(drive, &cmd);
 312
 313         *bcount = (cmd.tf.lbah << 8) | cmd.tf.lbam;
 314         *ireason = cmd.tf.nsect & 3;
 315 }
 316 EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);
 317
 318 /*
 319  * This is the usual interrupt handler which will be called during a packet
 320  * command.  We will transfer some of the data (as requested by the drive)
 321  * and will re-point interrupt handler to us.
 322  */
 323 static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 324 {
 325         struct ide_atapi_pc *pc = drive->pc;
 326         ide_hwif_t *hwif = drive->hwif;
 327         struct request *rq = hwif->rq;
 328         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 329         xfer_func_t *xferfunc;
 330         unsigned int timeout, temp;
 331         u16 bcount;
 332         u8 stat, ireason, dsc = 0;
 333
 334         debug_log("Enter %s - interrupt handler\n", __func__);
 335
 336         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 337                                                : WAIT_TAPE_CMD;
 338
 339         /* Clear the interrupt */
 340         stat = tp_ops->read_status(hwif);
 341
 342         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 343                 if (hwif->dma_ops->dma_end(drive) ||
 344                     (drive->media == ide_tape && (stat & ATA_ERR))) {
 345                         if (drive->media == ide_floppy)
 346                                 printk(KERN_ERR "%s: DMA %s error\n",
 347                                         drive->name, rq_data_dir(pc->rq)
 348                                                      ? "write" : "read");
 349                         pc->flags |= PC_FLAG_DMA_ERROR;
 350                 } else {
 351                         pc->xferred = pc->req_xfer;
 352                         if (drive->pc_update_buffers)
 353                                 drive->pc_update_buffers(drive, pc);
 354                 }
 355                 debug_log("%s: DMA finished\n", drive->name);
 356         }
 357
 358         /* No more interrupts */
 359         if ((stat & ATA_DRQ) == 0) {
 360                 int uptodate;
 361
 362                 debug_log("Packet command completed, %d bytes transferred\n",
 363                           pc->xferred);
 364
 365                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 366
 367                 local_irq_enable_in_hardirq();
 368
 369                 if (drive->media == ide_tape &&
 370                     (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
 371                         stat &= ~ATA_ERR;
 372
 373                 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
 374                         /* Error detected */
 375                         debug_log("%s: I/O error\n", drive->name);
 376
 377                         if (drive->media != ide_tape)
 378                                 pc->rq->errors++;
 379
 380                         if (rq->cmd[0] == REQUEST_SENSE) {
 381                                 printk(KERN_ERR "%s: I/O error in request sense"
 382                                                 " command\n", drive->name);
 383                                 return ide_do_reset(drive);
 384                         }
 385
 386                         debug_log("[cmd %x]: check condition\n", rq->cmd[0]);
 387
 388                         /* Retry operation */
 389                         ide_retry_pc(drive, rq->rq_disk);
 390
 391                         /* queued, but not started */
 392                         return ide_stopped;
 393                 }
 394                 pc->error = 0;
 395
 396                 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
 397                         dsc = 1;
 398
 399                 /* Command finished - Call the callback function */
 400                 uptodate = drive->pc_callback(drive, dsc);
 401
 402                 if (uptodate == 0)
 403                         drive->failed_pc = NULL;
 404
 405                 if (blk_special_request(rq)) {
 406                         rq->errors = 0;
 407                         ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 408                 } else {
 409                         if (blk_fs_request(rq) == 0 && uptodate <= 0) {
 410                                 if (rq->errors == 0)
 411                                         rq->errors = -EIO;
 412                         }
 413                         ide_complete_rq(drive, uptodate ? 0 : -EIO,
 414                                         ide_rq_bytes(rq));
 415                 }
 416
 417                 return ide_stopped;
 418         }
 419
 420         if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
 421                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 422                 printk(KERN_ERR "%s: The device wants to issue more interrupts "
 423                                 "in DMA mode\n", drive->name);
 424                 ide_dma_off(drive);
 425                 return ide_do_reset(drive);
 426         }
 427
 428         /* Get the number of bytes to transfer on this interrupt. */
 429         ide_read_bcount_and_ireason(drive, &bcount, &ireason);
 430
 431         if (ireason & ATAPI_COD) {
 432                 printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
 433                 return ide_do_reset(drive);
 434         }
 435
 436         if (((ireason & ATAPI_IO) == ATAPI_IO) ==
 437                 !!(pc->flags & PC_FLAG_WRITING)) {
 438                 /* Hopefully, we will never get here */
 439                 printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
 440                                 "to %s!\n", drive->name,
 441                                 (ireason & ATAPI_IO) ? "Write" : "Read",
 442                                 (ireason & ATAPI_IO) ? "Read" : "Write");
 443                 return ide_do_reset(drive);
 444         }
 445
 446         if (!(pc->flags & PC_FLAG_WRITING)) {
 447                 /* Reading - Check that we have enough space */
 448                 temp = pc->xferred + bcount;
 449                 if (temp > pc->req_xfer) {
 450                         if (temp > pc->buf_size) {
 451                                 printk(KERN_ERR "%s: The device wants to send "
 452                                                 "us more data than expected - "
 453                                                 "discarding data\n",
 454                                                 drive->name);
 455
 456                                 ide_pad_transfer(drive, 0, bcount);
 457                                 goto next_irq;
 458                         }
 459                         debug_log("The device wants to send us more data than "
 460                                   "expected - allowing transfer\n");
 461                 }
 462                 xferfunc = tp_ops->input_data;
 463         } else
 464                 xferfunc = tp_ops->output_data;
 465
 466         if ((drive->media == ide_floppy && !pc->buf) ||
 467             (drive->media == ide_tape && pc->bh)) {
 468                 int done = drive->pc_io_buffers(drive, pc, bcount,
 469                                   !!(pc->flags & PC_FLAG_WRITING));
 470
 471                 /* FIXME: don't do partial completions */
 472                 if (drive->media == ide_floppy)
 473                         ide_complete_rq(drive, 0,
 474                                         done ? done : ide_rq_bytes(rq));
 475         } else
 476                 xferfunc(drive, NULL, pc->cur_pos, bcount);
 477
 478         /* Update the current position */
 479         pc->xferred += bcount;
 480         pc->cur_pos += bcount;
 481
 482         debug_log("[cmd %x] transferred %d bytes on that intr.\n",
 483                   rq->cmd[0], bcount);
 484 next_irq:
 485         /* And set the interrupt handler again */
 486         ide_set_handler(drive, ide_pc_intr, timeout, NULL);
 487         return ide_started;
 488 }
 489
 490 static void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount)
 491 {
 492         ide_hwif_t *hwif = drive->hwif;
 493         struct ide_cmd cmd;
 494         u8 dma = drive->dma;
 495
 496         memset(&cmd, 0, sizeof(cmd));
 497         cmd.tf_flags = IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM |
 498                        IDE_TFLAG_OUT_FEATURE | tf_flags;
 499         cmd.tf.feature = dma;           /* Use PIO/DMA */
 500         cmd.tf.lbam    = bcount & 0xff;
 501         cmd.tf.lbah    = (bcount >> 8) & 0xff;
 502
 503         ide_tf_dump(drive->name, &cmd.tf);
 504         hwif->tp_ops->set_irq(hwif, 1);
 505         SELECT_MASK(drive, 0);
 506         hwif->tp_ops->tf_load(drive, &cmd);
 507 }
 508
 509 static u8 ide_read_ireason(ide_drive_t *drive)
 510 {
 511         struct ide_cmd cmd;
 512
 513         memset(&cmd, 0, sizeof(cmd));
 514         cmd.tf_flags = IDE_TFLAG_IN_NSECT;
 515
 516         drive->hwif->tp_ops->tf_read(drive, &cmd);
 517
 518         return cmd.tf.nsect & 3;
 519 }
 520
 521 static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
 522 {
 523         int retries = 100;
 524
 525         while (retries-- && ((ireason & ATAPI_COD) == 0 ||
 526                 (ireason & ATAPI_IO))) {
 527                 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
 528                                 "a packet command, retrying\n", drive->name);
 529                 udelay(100);
 530                 ireason = ide_read_ireason(drive);
 531                 if (retries == 0) {
 532                         printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
 533                                         "a packet command, ignoring\n",
 534                                         drive->name);
 535                         ireason |= ATAPI_COD;
 536                         ireason &= ~ATAPI_IO;
 537                 }
 538         }
 539
 540         return ireason;
 541 }
 542
 543 static int ide_delayed_transfer_pc(ide_drive_t *drive)
 544 {
 545         /* Send the actual packet */
 546         drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);
 547
 548         /* Timeout for the packet command */
 549         return WAIT_FLOPPY_CMD;
 550 }
 551
 552 static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
 553 {
 554         struct ide_atapi_pc *uninitialized_var(pc);
 555         ide_hwif_t *hwif = drive->hwif;
 556         struct request *rq = hwif->rq;
 557         ide_expiry_t *expiry;
 558         unsigned int timeout;
 559         int cmd_len;
 560         ide_startstop_t startstop;
 561         u8 ireason;
 562
 563         if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
 564                 printk(KERN_ERR "%s: Strange, packet command initiated yet "
 565                                 "DRQ isn't asserted\n", drive->name);
 566                 return startstop;
 567         }
 568
 569         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 570                 if (drive->dma)
 571                         drive->waiting_for_dma = 1;
 572         }
 573
 574         if (dev_is_idecd(drive)) {
 575                 /* ATAPI commands get padded out to 12 bytes minimum */
 576                 cmd_len = COMMAND_SIZE(rq->cmd[0]);
 577                 if (cmd_len < ATAPI_MIN_CDB_BYTES)
 578                         cmd_len = ATAPI_MIN_CDB_BYTES;
 579
 580                 timeout = rq->timeout;
 581                 expiry  = ide_cd_expiry;
 582         } else {
 583                 pc = drive->pc;
 584
 585                 cmd_len = ATAPI_MIN_CDB_BYTES;
 586
 587                 /*
 588                  * If necessary schedule the packet transfer to occur 'timeout'
 589                  * miliseconds later in ide_delayed_transfer_pc() after the
 590                  * device says it's ready for a packet.
 591                  */
 592                 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
 593                         timeout = drive->pc_delay;
 594                         expiry = &ide_delayed_transfer_pc;
 595                 } else {
 596                         timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 597                                                                : WAIT_TAPE_CMD;
 598                         expiry = NULL;
 599                 }
 600
 601                 ireason = ide_read_ireason(drive);
 602                 if (drive->media == ide_tape)
 603                         ireason = ide_wait_ireason(drive, ireason);
 604
 605                 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
 606                         printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
 607                                         "a packet command\n", drive->name);
 608
 609                         return ide_do_reset(drive);
 610                 }
 611         }
 612
 613         /* Set the interrupt routine */
 614         ide_set_handler(drive,
 615                         (dev_is_idecd(drive) ? drive->irq_handler
 616                                              : ide_pc_intr),
 617                         timeout, expiry);
 618
 619         /* Begin DMA, if necessary */
 620         if (dev_is_idecd(drive)) {
 621                 if (drive->dma)
 622                         hwif->dma_ops->dma_start(drive);
 623         } else {
 624                 if (pc->flags & PC_FLAG_DMA_OK) {
 625                         pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
 626                         hwif->dma_ops->dma_start(drive);
 627                 }
 628         }
 629
 630         /* Send the actual packet */
 631         if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
 632                 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);
 633
 634         return ide_started;
 635 }
 636
 637 ide_startstop_t ide_issue_pc(ide_drive_t *drive)
 638 {
 639         struct ide_atapi_pc *pc;
 640         ide_hwif_t *hwif = drive->hwif;
 641         ide_expiry_t *expiry = NULL;
 642         struct request *rq = hwif->rq;
 643         unsigned int timeout;
 644         u32 tf_flags;
 645         u16 bcount;
 646
 647         if (dev_is_idecd(drive)) {
 648                 tf_flags = IDE_TFLAG_OUT_NSECT | IDE_TFLAG_OUT_LBAL;
 649                 bcount = ide_cd_get_xferlen(rq);
 650                 expiry = ide_cd_expiry;
 651                 timeout = ATAPI_WAIT_PC;
 652
 653                 if (drive->dma) {
 654                         if (ide_build_sglist(drive, rq))
 655                                 drive->dma = !hwif->dma_ops->dma_setup(drive);
 656                         else
 657                                 drive->dma = 0;
 658                 }
 659         } else {
 660                 pc = drive->pc;
 661
 662                 /* We haven't transferred any data yet */
 663                 pc->xferred = 0;
 664                 pc->cur_pos = pc->buf;
 665
 666                 tf_flags = IDE_TFLAG_OUT_DEVICE;
 667                 bcount = ((drive->media == ide_tape) ?
 668                                 pc->req_xfer :
 669                                 min(pc->req_xfer, 63 * 1024));
 670
 671                 if (pc->flags & PC_FLAG_DMA_ERROR) {
 672                         pc->flags &= ~PC_FLAG_DMA_ERROR;
 673                         ide_dma_off(drive);
 674                 }
 675
 676                 if ((pc->flags & PC_FLAG_DMA_OK) &&
 677                      (drive->dev_flags & IDE_DFLAG_USING_DMA)) {
 678                         if (ide_build_sglist(drive, rq))
 679                                 drive->dma = !hwif->dma_ops->dma_setup(drive);
 680                         else
 681                                 drive->dma = 0;
 682                 }
 683
 684                 if (!drive->dma)
 685                         pc->flags &= ~PC_FLAG_DMA_OK;
 686
 687                 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
 688                                                        : WAIT_TAPE_CMD;
 689         }
 690
 691         ide_pktcmd_tf_load(drive, tf_flags, bcount);
 692
 693         /* Issue the packet command */
 694         if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
 695                 if (drive->dma)
 696                         drive->waiting_for_dma = 0;
 697                 ide_execute_command(drive, ATA_CMD_PACKET, ide_transfer_pc,
 698                                     timeout, expiry);
 699                 return ide_started;
 700         } else {
 701                 ide_execute_pkt_cmd(drive);
 702                 return ide_transfer_pc(drive);
 703         }
 704 }
 705 EXPORT_SYMBOL_GPL(ide_issue_pc);