ide-atapi.c revision f094d4d83bccee9277ddb6aadccf35747889426b
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 <linux/scatterlist.h> 10 11#include <scsi/scsi.h> 12 13#ifdef DEBUG 14#define debug_log(fmt, args...) \ 15 printk(KERN_INFO "ide: " fmt, ## args) 16#else 17#define debug_log(fmt, args...) do {} while (0) 18#endif 19 20#define ATAPI_MIN_CDB_BYTES 12 21 22static inline int dev_is_idecd(ide_drive_t *drive) 23{ 24 return drive->media == ide_cdrom || drive->media == ide_optical; 25} 26 27/* 28 * Check whether we can support a device, 29 * based on the ATAPI IDENTIFY command results. 30 */ 31int ide_check_atapi_device(ide_drive_t *drive, const char *s) 32{ 33 u16 *id = drive->id; 34 u8 gcw[2], protocol, device_type, removable, drq_type, packet_size; 35 36 *((u16 *)&gcw) = id[ATA_ID_CONFIG]; 37 38 protocol = (gcw[1] & 0xC0) >> 6; 39 device_type = gcw[1] & 0x1F; 40 removable = (gcw[0] & 0x80) >> 7; 41 drq_type = (gcw[0] & 0x60) >> 5; 42 packet_size = gcw[0] & 0x03; 43 44#ifdef CONFIG_PPC 45 /* kludge for Apple PowerBook internal zip */ 46 if (drive->media == ide_floppy && device_type == 5 && 47 !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") && 48 strstr((char *)&id[ATA_ID_PROD], "ZIP")) 49 device_type = 0; 50#endif 51 52 if (protocol != 2) 53 printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n", 54 s, drive->name, protocol); 55 else if ((drive->media == ide_floppy && device_type != 0) || 56 (drive->media == ide_tape && device_type != 1)) 57 printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n", 58 s, drive->name, device_type); 59 else if (removable == 0) 60 printk(KERN_ERR "%s: %s: the removable flag is not set\n", 61 s, drive->name); 62 else if (drive->media == ide_floppy && drq_type == 3) 63 printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not " 64 "supported\n", s, drive->name, drq_type); 65 else if (packet_size != 0) 66 printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 " 67 "bytes\n", s, drive->name, packet_size); 68 else 69 return 1; 70 return 0; 71} 72EXPORT_SYMBOL_GPL(ide_check_atapi_device); 73 74/* PIO data transfer routine using the scatter gather table. */ 75int ide_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc, 76 unsigned int bcount, int write) 77{ 78 ide_hwif_t *hwif = drive->hwif; 79 const struct ide_tp_ops *tp_ops = hwif->tp_ops; 80 xfer_func_t *xf = write ? tp_ops->output_data : tp_ops->input_data; 81 struct scatterlist *sg = pc->sg; 82 char *buf; 83 int count, done = 0; 84 85 while (bcount) { 86 count = min(sg->length - pc->b_count, bcount); 87 88 if (PageHighMem(sg_page(sg))) { 89 unsigned long flags; 90 91 local_irq_save(flags); 92 buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset; 93 xf(drive, NULL, buf + pc->b_count, count); 94 kunmap_atomic(buf - sg->offset, KM_IRQ0); 95 local_irq_restore(flags); 96 } else { 97 buf = sg_virt(sg); 98 xf(drive, NULL, buf + pc->b_count, count); 99 } 100 101 bcount -= count; 102 pc->b_count += count; 103 done += count; 104 105 if (pc->b_count == sg->length) { 106 if (!--pc->sg_cnt) 107 break; 108 pc->sg = sg = sg_next(sg); 109 pc->b_count = 0; 110 } 111 } 112 113 if (bcount) { 114 printk(KERN_ERR "%s: %d leftover bytes, %s\n", drive->name, 115 bcount, write ? "padding with zeros" 116 : "discarding data"); 117 ide_pad_transfer(drive, write, bcount); 118 } 119 120 return done; 121} 122EXPORT_SYMBOL_GPL(ide_io_buffers); 123 124void ide_init_pc(struct ide_atapi_pc *pc) 125{ 126 memset(pc, 0, sizeof(*pc)); 127 pc->buf = pc->pc_buf; 128 pc->buf_size = IDE_PC_BUFFER_SIZE; 129} 130EXPORT_SYMBOL_GPL(ide_init_pc); 131 132/* 133 * Generate a new packet command request in front of the request queue, before 134 * the current request, so that it will be processed immediately, on the next 135 * pass through the driver. 136 */ 137static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk, 138 struct ide_atapi_pc *pc, struct request *rq) 139{ 140 blk_rq_init(NULL, rq); 141 rq->cmd_type = REQ_TYPE_SPECIAL; 142 rq->cmd_flags |= REQ_PREEMPT; 143 rq->buffer = (char *)pc; 144 rq->rq_disk = disk; 145 146 if (pc->req_xfer) { 147 rq->data = pc->buf; 148 rq->data_len = pc->req_xfer; 149 } 150 151 memcpy(rq->cmd, pc->c, 12); 152 if (drive->media == ide_tape) 153 rq->cmd[13] = REQ_IDETAPE_PC1; 154 155 drive->hwif->rq = NULL; 156 157 elv_add_request(drive->queue, rq, ELEVATOR_INSERT_FRONT, 0); 158} 159 160/* 161 * Add a special packet command request to the tail of the request queue, 162 * and wait for it to be serviced. 163 */ 164int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk, 165 struct ide_atapi_pc *pc) 166{ 167 struct request *rq; 168 int error; 169 170 rq = blk_get_request(drive->queue, READ, __GFP_WAIT); 171 rq->cmd_type = REQ_TYPE_SPECIAL; 172 rq->buffer = (char *)pc; 173 174 if (pc->req_xfer) { 175 rq->data = pc->buf; 176 rq->data_len = pc->req_xfer; 177 } 178 179 memcpy(rq->cmd, pc->c, 12); 180 if (drive->media == ide_tape) 181 rq->cmd[13] = REQ_IDETAPE_PC1; 182 error = blk_execute_rq(drive->queue, disk, rq, 0); 183 blk_put_request(rq); 184 185 return error; 186} 187EXPORT_SYMBOL_GPL(ide_queue_pc_tail); 188 189int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk) 190{ 191 struct ide_atapi_pc pc; 192 193 ide_init_pc(&pc); 194 pc.c[0] = TEST_UNIT_READY; 195 196 return ide_queue_pc_tail(drive, disk, &pc); 197} 198EXPORT_SYMBOL_GPL(ide_do_test_unit_ready); 199 200int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start) 201{ 202 struct ide_atapi_pc pc; 203 204 ide_init_pc(&pc); 205 pc.c[0] = START_STOP; 206 pc.c[4] = start; 207 208 if (drive->media == ide_tape) 209 pc.flags |= PC_FLAG_WAIT_FOR_DSC; 210 211 return ide_queue_pc_tail(drive, disk, &pc); 212} 213EXPORT_SYMBOL_GPL(ide_do_start_stop); 214 215int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on) 216{ 217 struct ide_atapi_pc pc; 218 219 if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0) 220 return 0; 221 222 ide_init_pc(&pc); 223 pc.c[0] = ALLOW_MEDIUM_REMOVAL; 224 pc.c[4] = on; 225 226 return ide_queue_pc_tail(drive, disk, &pc); 227} 228EXPORT_SYMBOL_GPL(ide_set_media_lock); 229 230void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc) 231{ 232 ide_init_pc(pc); 233 pc->c[0] = REQUEST_SENSE; 234 if (drive->media == ide_floppy) { 235 pc->c[4] = 255; 236 pc->req_xfer = 18; 237 } else { 238 pc->c[4] = 20; 239 pc->req_xfer = 20; 240 } 241} 242EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd); 243 244/* 245 * Called when an error was detected during the last packet command. 246 * We queue a request sense packet command in the head of the request list. 247 */ 248void ide_retry_pc(ide_drive_t *drive, struct gendisk *disk) 249{ 250 struct request *rq = &drive->request_sense_rq; 251 struct ide_atapi_pc *pc = &drive->request_sense_pc; 252 253 (void)ide_read_error(drive); 254 ide_create_request_sense_cmd(drive, pc); 255 if (drive->media == ide_tape) 256 set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags); 257 ide_queue_pc_head(drive, disk, pc, rq); 258} 259EXPORT_SYMBOL_GPL(ide_retry_pc); 260 261int ide_cd_expiry(ide_drive_t *drive) 262{ 263 struct request *rq = drive->hwif->rq; 264 unsigned long wait = 0; 265 266 debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]); 267 268 /* 269 * Some commands are *slow* and normally take a long time to complete. 270 * Usually we can use the ATAPI "disconnect" to bypass this, but not all 271 * commands/drives support that. Let ide_timer_expiry keep polling us 272 * for these. 273 */ 274 switch (rq->cmd[0]) { 275 case GPCMD_BLANK: 276 case GPCMD_FORMAT_UNIT: 277 case GPCMD_RESERVE_RZONE_TRACK: 278 case GPCMD_CLOSE_TRACK: 279 case GPCMD_FLUSH_CACHE: 280 wait = ATAPI_WAIT_PC; 281 break; 282 default: 283 if (!(rq->cmd_flags & REQ_QUIET)) 284 printk(KERN_INFO "cmd 0x%x timed out\n", 285 rq->cmd[0]); 286 wait = 0; 287 break; 288 } 289 return wait; 290} 291EXPORT_SYMBOL_GPL(ide_cd_expiry); 292 293int ide_cd_get_xferlen(struct request *rq) 294{ 295 if (blk_fs_request(rq)) 296 return 32768; 297 else if (blk_sense_request(rq) || blk_pc_request(rq) || 298 rq->cmd_type == REQ_TYPE_ATA_PC) 299 return rq->data_len; 300 else 301 return 0; 302} 303EXPORT_SYMBOL_GPL(ide_cd_get_xferlen); 304 305void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason) 306{ 307 struct ide_cmd cmd; 308 309 memset(&cmd, 0, sizeof(cmd)); 310 cmd.tf_flags = IDE_TFLAG_IN_LBAH | IDE_TFLAG_IN_LBAM | 311 IDE_TFLAG_IN_NSECT; 312 313 drive->hwif->tp_ops->tf_read(drive, &cmd); 314 315 *bcount = (cmd.tf.lbah << 8) | cmd.tf.lbam; 316 *ireason = cmd.tf.nsect & 3; 317} 318EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason); 319 320/* 321 * This is the usual interrupt handler which will be called during a packet 322 * command. We will transfer some of the data (as requested by the drive) 323 * and will re-point interrupt handler to us. 324 */ 325static ide_startstop_t ide_pc_intr(ide_drive_t *drive) 326{ 327 struct ide_atapi_pc *pc = drive->pc; 328 ide_hwif_t *hwif = drive->hwif; 329 struct ide_cmd *cmd = &hwif->cmd; 330 struct request *rq = hwif->rq; 331 const struct ide_tp_ops *tp_ops = hwif->tp_ops; 332 xfer_func_t *xferfunc; 333 unsigned int timeout, temp; 334 u16 bcount; 335 u8 stat, ireason, dsc = 0; 336 337 debug_log("Enter %s - interrupt handler\n", __func__); 338 339 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 340 : WAIT_TAPE_CMD; 341 342 /* Clear the interrupt */ 343 stat = tp_ops->read_status(hwif); 344 345 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 346 int rc; 347 348 drive->waiting_for_dma = 0; 349 rc = hwif->dma_ops->dma_end(drive); 350 ide_dma_unmap_sg(drive, cmd); 351 352 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) { 353 if (drive->media == ide_floppy) 354 printk(KERN_ERR "%s: DMA %s error\n", 355 drive->name, rq_data_dir(pc->rq) 356 ? "write" : "read"); 357 pc->flags |= PC_FLAG_DMA_ERROR; 358 } else { 359 pc->xferred = pc->req_xfer; 360 if (drive->pc_update_buffers) 361 drive->pc_update_buffers(drive, pc); 362 } 363 debug_log("%s: DMA finished\n", drive->name); 364 } 365 366 /* No more interrupts */ 367 if ((stat & ATA_DRQ) == 0) { 368 int uptodate; 369 370 debug_log("Packet command completed, %d bytes transferred\n", 371 pc->xferred); 372 373 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 374 375 local_irq_enable_in_hardirq(); 376 377 if (drive->media == ide_tape && 378 (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE) 379 stat &= ~ATA_ERR; 380 381 if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) { 382 /* Error detected */ 383 debug_log("%s: I/O error\n", drive->name); 384 385 if (drive->media != ide_tape) 386 pc->rq->errors++; 387 388 if (rq->cmd[0] == REQUEST_SENSE) { 389 printk(KERN_ERR "%s: I/O error in request sense" 390 " command\n", drive->name); 391 return ide_do_reset(drive); 392 } 393 394 debug_log("[cmd %x]: check condition\n", rq->cmd[0]); 395 396 /* Retry operation */ 397 ide_retry_pc(drive, rq->rq_disk); 398 399 /* queued, but not started */ 400 return ide_stopped; 401 } 402 pc->error = 0; 403 404 if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0) 405 dsc = 1; 406 407 /* Command finished - Call the callback function */ 408 uptodate = drive->pc_callback(drive, dsc); 409 410 if (uptodate == 0) 411 drive->failed_pc = NULL; 412 413 if (blk_special_request(rq)) { 414 rq->errors = 0; 415 ide_complete_rq(drive, 0, blk_rq_bytes(rq)); 416 } else { 417 if (blk_fs_request(rq) == 0 && uptodate <= 0) { 418 if (rq->errors == 0) 419 rq->errors = -EIO; 420 } 421 ide_complete_rq(drive, uptodate ? 0 : -EIO, 422 ide_rq_bytes(rq)); 423 } 424 425 return ide_stopped; 426 } 427 428 if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) { 429 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS; 430 printk(KERN_ERR "%s: The device wants to issue more interrupts " 431 "in DMA mode\n", drive->name); 432 ide_dma_off(drive); 433 return ide_do_reset(drive); 434 } 435 436 /* Get the number of bytes to transfer on this interrupt. */ 437 ide_read_bcount_and_ireason(drive, &bcount, &ireason); 438 439 if (ireason & ATAPI_COD) { 440 printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__); 441 return ide_do_reset(drive); 442 } 443 444 if (((ireason & ATAPI_IO) == ATAPI_IO) == 445 !!(pc->flags & PC_FLAG_WRITING)) { 446 /* Hopefully, we will never get here */ 447 printk(KERN_ERR "%s: We wanted to %s, but the device wants us " 448 "to %s!\n", drive->name, 449 (ireason & ATAPI_IO) ? "Write" : "Read", 450 (ireason & ATAPI_IO) ? "Read" : "Write"); 451 return ide_do_reset(drive); 452 } 453 454 if (!(pc->flags & PC_FLAG_WRITING)) { 455 /* Reading - Check that we have enough space */ 456 temp = pc->xferred + bcount; 457 if (temp > pc->req_xfer) { 458 if (temp > pc->buf_size) { 459 printk(KERN_ERR "%s: The device wants to send " 460 "us more data than expected - " 461 "discarding data\n", 462 drive->name); 463 464 ide_pad_transfer(drive, 0, bcount); 465 goto next_irq; 466 } 467 debug_log("The device wants to send us more data than " 468 "expected - allowing transfer\n"); 469 } 470 xferfunc = tp_ops->input_data; 471 } else 472 xferfunc = tp_ops->output_data; 473 474 if ((drive->media == ide_floppy && !pc->buf) || 475 (drive->media == ide_tape && pc->bh)) { 476 int done = drive->pc_io_buffers(drive, pc, bcount, 477 !!(pc->flags & PC_FLAG_WRITING)); 478 479 /* FIXME: don't do partial completions */ 480 if (drive->media == ide_floppy) 481 ide_complete_rq(drive, 0, 482 done ? done : ide_rq_bytes(rq)); 483 } else 484 xferfunc(drive, NULL, pc->cur_pos, bcount); 485 486 /* Update the current position */ 487 pc->xferred += bcount; 488 pc->cur_pos += bcount; 489 490 debug_log("[cmd %x] transferred %d bytes on that intr.\n", 491 rq->cmd[0], bcount); 492next_irq: 493 /* And set the interrupt handler again */ 494 ide_set_handler(drive, ide_pc_intr, timeout); 495 return ide_started; 496} 497 498static void ide_init_packet_cmd(struct ide_cmd *cmd, u32 tf_flags, 499 u16 bcount, u8 dma) 500{ 501 cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO; 502 cmd->tf_flags |= IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM | 503 IDE_TFLAG_OUT_FEATURE | tf_flags; 504 cmd->tf.command = ATA_CMD_PACKET; 505 cmd->tf.feature = dma; /* Use PIO/DMA */ 506 cmd->tf.lbam = bcount & 0xff; 507 cmd->tf.lbah = (bcount >> 8) & 0xff; 508} 509 510static u8 ide_read_ireason(ide_drive_t *drive) 511{ 512 struct ide_cmd cmd; 513 514 memset(&cmd, 0, sizeof(cmd)); 515 cmd.tf_flags = IDE_TFLAG_IN_NSECT; 516 517 drive->hwif->tp_ops->tf_read(drive, &cmd); 518 519 return cmd.tf.nsect & 3; 520} 521 522static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason) 523{ 524 int retries = 100; 525 526 while (retries-- && ((ireason & ATAPI_COD) == 0 || 527 (ireason & ATAPI_IO))) { 528 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing " 529 "a packet command, retrying\n", drive->name); 530 udelay(100); 531 ireason = ide_read_ireason(drive); 532 if (retries == 0) { 533 printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing " 534 "a packet command, ignoring\n", 535 drive->name); 536 ireason |= ATAPI_COD; 537 ireason &= ~ATAPI_IO; 538 } 539 } 540 541 return ireason; 542} 543 544static int ide_delayed_transfer_pc(ide_drive_t *drive) 545{ 546 /* Send the actual packet */ 547 drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12); 548 549 /* Timeout for the packet command */ 550 return WAIT_FLOPPY_CMD; 551} 552 553static ide_startstop_t ide_transfer_pc(ide_drive_t *drive) 554{ 555 struct ide_atapi_pc *uninitialized_var(pc); 556 ide_hwif_t *hwif = drive->hwif; 557 struct request *rq = hwif->rq; 558 ide_expiry_t *expiry; 559 unsigned int timeout; 560 int cmd_len; 561 ide_startstop_t startstop; 562 u8 ireason; 563 564 if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) { 565 printk(KERN_ERR "%s: Strange, packet command initiated yet " 566 "DRQ isn't asserted\n", drive->name); 567 return startstop; 568 } 569 570 if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) { 571 if (drive->dma) 572 drive->waiting_for_dma = 1; 573 } 574 575 if (dev_is_idecd(drive)) { 576 /* ATAPI commands get padded out to 12 bytes minimum */ 577 cmd_len = COMMAND_SIZE(rq->cmd[0]); 578 if (cmd_len < ATAPI_MIN_CDB_BYTES) 579 cmd_len = ATAPI_MIN_CDB_BYTES; 580 581 timeout = rq->timeout; 582 expiry = ide_cd_expiry; 583 } else { 584 pc = drive->pc; 585 586 cmd_len = ATAPI_MIN_CDB_BYTES; 587 588 /* 589 * If necessary schedule the packet transfer to occur 'timeout' 590 * miliseconds later in ide_delayed_transfer_pc() after the 591 * device says it's ready for a packet. 592 */ 593 if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) { 594 timeout = drive->pc_delay; 595 expiry = &ide_delayed_transfer_pc; 596 } else { 597 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 598 : WAIT_TAPE_CMD; 599 expiry = NULL; 600 } 601 602 ireason = ide_read_ireason(drive); 603 if (drive->media == ide_tape) 604 ireason = ide_wait_ireason(drive, ireason); 605 606 if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) { 607 printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing " 608 "a packet command\n", drive->name); 609 610 return ide_do_reset(drive); 611 } 612 } 613 614 hwif->expiry = expiry; 615 616 /* Set the interrupt routine */ 617 ide_set_handler(drive, 618 (dev_is_idecd(drive) ? drive->irq_handler 619 : ide_pc_intr), 620 timeout); 621 622 /* Send the actual packet */ 623 if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0) 624 hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len); 625 626 /* Begin DMA, if necessary */ 627 if (dev_is_idecd(drive)) { 628 if (drive->dma) 629 hwif->dma_ops->dma_start(drive); 630 } else { 631 if (pc->flags & PC_FLAG_DMA_OK) { 632 pc->flags |= PC_FLAG_DMA_IN_PROGRESS; 633 hwif->dma_ops->dma_start(drive); 634 } 635 } 636 637 return ide_started; 638} 639 640ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd) 641{ 642 struct ide_atapi_pc *pc; 643 ide_hwif_t *hwif = drive->hwif; 644 ide_expiry_t *expiry = NULL; 645 struct request *rq = hwif->rq; 646 unsigned int timeout; 647 u32 tf_flags; 648 u16 bcount; 649 u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT); 650 651 if (dev_is_idecd(drive)) { 652 tf_flags = IDE_TFLAG_OUT_NSECT | IDE_TFLAG_OUT_LBAL; 653 bcount = ide_cd_get_xferlen(rq); 654 expiry = ide_cd_expiry; 655 timeout = ATAPI_WAIT_PC; 656 657 if (drive->dma) 658 drive->dma = !ide_dma_prepare(drive, cmd); 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->dma = !ide_dma_prepare(drive, cmd); 678 679 if (!drive->dma) 680 pc->flags &= ~PC_FLAG_DMA_OK; 681 682 timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD 683 : WAIT_TAPE_CMD; 684 } 685 686 ide_init_packet_cmd(cmd, tf_flags, bcount, drive->dma); 687 688 (void)do_rw_taskfile(drive, cmd); 689 690 if (drq_int) { 691 if (drive->dma) 692 drive->waiting_for_dma = 0; 693 hwif->expiry = expiry; 694 } 695 696 ide_execute_command(drive, cmd, ide_transfer_pc, timeout); 697 698 return drq_int ? ide_started : ide_transfer_pc(drive); 699} 700EXPORT_SYMBOL_GPL(ide_issue_pc); 701