4 * Basic PIO and command management functionality.
6 * This code was split off from ide.c. See ide.c for history and original
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2, or (at your option) any
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * For the avoidance of doubt the "preferred form" of this code is one which
20 * is in an open non patent encumbered format. Where cryptographic key signing
21 * forms part of the process of creating an executable the information
22 * including keys needed to generate an equivalently functional executable
23 * are deemed to be part of the source code.
27 #include <linux/module.h>
28 #include <linux/types.h>
29 #include <linux/string.h>
30 #include <linux/kernel.h>
31 #include <linux/timer.h>
33 #include <linux/interrupt.h>
34 #include <linux/major.h>
35 #include <linux/errno.h>
36 #include <linux/genhd.h>
37 #include <linux/blkpg.h>
38 #include <linux/slab.h>
39 #include <linux/init.h>
40 #include <linux/pci.h>
41 #include <linux/delay.h>
42 #include <linux/ide.h>
43 #include <linux/completion.h>
44 #include <linux/reboot.h>
45 #include <linux/cdrom.h>
46 #include <linux/seq_file.h>
47 #include <linux/device.h>
48 #include <linux/kmod.h>
49 #include <linux/scatterlist.h>
50 #include <linux/bitops.h>
52 #include <asm/byteorder.h>
54 #include <asm/uaccess.h>
57 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
58 int uptodate, unsigned int nr_bytes, int dequeue)
64 error = uptodate ? uptodate : -EIO;
67 * if failfast is set on a request, override number of sectors and
68 * complete the whole request right now
70 if (blk_noretry_request(rq) && error)
71 nr_bytes = rq->hard_nr_sectors << 9;
73 if (!blk_fs_request(rq) && error && !rq->errors)
77 * decide whether to reenable DMA -- 3 is a random magic for now,
78 * if we DMA timeout more than 3 times, just stay in PIO
80 if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) &&
81 drive->retry_pio <= 3) {
82 drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY;
86 if (!blk_end_request(rq, error, nr_bytes))
89 if (ret == 0 && dequeue)
90 drive->hwif->rq = NULL;
96 * ide_end_request - complete an IDE I/O
97 * @drive: IDE device for the I/O
99 * @nr_sectors: number of sectors completed
101 * This is our end_request wrapper function. We complete the I/O
102 * update random number input and dequeue the request, which if
103 * it was tagged may be out of order.
106 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
108 unsigned int nr_bytes = nr_sectors << 9;
109 struct request *rq = drive->hwif->rq;
112 if (blk_pc_request(rq))
113 nr_bytes = rq->data_len;
115 nr_bytes = rq->hard_cur_sectors << 9;
118 return __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
120 EXPORT_SYMBOL(ide_end_request);
123 * ide_end_dequeued_request - complete an IDE I/O
124 * @drive: IDE device for the I/O
126 * @nr_sectors: number of sectors completed
128 * Complete an I/O that is no longer on the request queue. This
129 * typically occurs when we pull the request and issue a REQUEST_SENSE.
130 * We must still finish the old request but we must not tamper with the
131 * queue in the meantime.
133 * NOTE: This path does not handle barrier, but barrier is not supported
137 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
138 int uptodate, int nr_sectors)
140 BUG_ON(!blk_rq_started(rq));
142 return __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
144 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
146 void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
148 struct ide_taskfile *tf = &cmd->tf;
149 struct request *rq = cmd->rq;
154 drive->hwif->tp_ops->tf_read(drive, cmd);
156 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
157 memcpy(rq->special, cmd, sizeof(*cmd));
159 if (cmd->tf_flags & IDE_TFLAG_DYN)
163 void ide_complete_rq(ide_drive_t *drive, u8 err)
165 ide_hwif_t *hwif = drive->hwif;
166 struct request *rq = hwif->rq;
172 if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0),
176 EXPORT_SYMBOL(ide_complete_rq);
178 void ide_kill_rq(ide_drive_t *drive, struct request *rq)
180 u8 drv_req = blk_special_request(rq) && rq->rq_disk;
181 u8 media = drive->media;
183 drive->failed_pc = NULL;
185 if ((media == ide_floppy && drv_req) || media == ide_tape)
186 rq->errors = IDE_DRV_ERROR_GENERAL;
188 if ((media == ide_floppy || media == ide_tape) && drv_req)
189 ide_complete_rq(drive, 0);
191 ide_end_request(drive, 0, 0);
194 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
196 tf->nsect = drive->sect;
197 tf->lbal = drive->sect;
198 tf->lbam = drive->cyl;
199 tf->lbah = drive->cyl >> 8;
200 tf->device = (drive->head - 1) | drive->select;
201 tf->command = ATA_CMD_INIT_DEV_PARAMS;
204 static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
206 tf->nsect = drive->sect;
207 tf->command = ATA_CMD_RESTORE;
210 static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
212 tf->nsect = drive->mult_req;
213 tf->command = ATA_CMD_SET_MULTI;
216 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
218 special_t *s = &drive->special;
221 memset(&cmd, 0, sizeof(cmd));
222 cmd.protocol = ATA_PROT_NODATA;
224 if (s->b.set_geometry) {
225 s->b.set_geometry = 0;
226 ide_tf_set_specify_cmd(drive, &cmd.tf);
227 } else if (s->b.recalibrate) {
228 s->b.recalibrate = 0;
229 ide_tf_set_restore_cmd(drive, &cmd.tf);
230 } else if (s->b.set_multmode) {
231 s->b.set_multmode = 0;
232 ide_tf_set_setmult_cmd(drive, &cmd.tf);
234 int special = s->all;
236 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
240 cmd.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE |
241 IDE_TFLAG_CUSTOM_HANDLER;
243 do_rw_taskfile(drive, &cmd);
249 * do_special - issue some special commands
250 * @drive: drive the command is for
252 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
253 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
255 * It used to do much more, but has been scaled back.
258 static ide_startstop_t do_special (ide_drive_t *drive)
260 special_t *s = &drive->special;
263 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
265 if (drive->media == ide_disk)
266 return ide_disk_special(drive);
273 void ide_map_sg(ide_drive_t *drive, struct request *rq)
275 ide_hwif_t *hwif = drive->hwif;
276 struct ide_cmd *cmd = &hwif->cmd;
277 struct scatterlist *sg = hwif->sg_table;
279 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
280 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
282 } else if (!rq->bio) {
283 sg_init_one(sg, rq->data, rq->data_len);
286 cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
288 EXPORT_SYMBOL_GPL(ide_map_sg);
290 void ide_init_sg_cmd(struct ide_cmd *cmd, int nsect)
292 cmd->nsect = cmd->nleft = nsect;
296 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
299 * execute_drive_command - issue special drive command
300 * @drive: the drive to issue the command on
301 * @rq: the request structure holding the command
303 * execute_drive_cmd() issues a special drive command, usually
304 * initiated by ioctl() from the external hdparm program. The
305 * command can be a drive command, drive task or taskfile
306 * operation. Weirdly you can call it with NULL to wait for
307 * all commands to finish. Don't do this as that is due to change
310 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
313 struct ide_cmd *cmd = rq->special;
316 if (cmd->protocol == ATA_PROT_PIO) {
317 ide_init_sg_cmd(cmd, rq->nr_sectors);
318 ide_map_sg(drive, rq);
321 return do_rw_taskfile(drive, cmd);
325 * NULL is actually a valid way of waiting for
326 * all current requests to be flushed from the queue.
329 printk("%s: DRIVE_CMD (null)\n", drive->name);
331 ide_complete_rq(drive, 0);
336 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
342 case REQ_UNPARK_HEADS:
343 return ide_do_park_unpark(drive, rq);
344 case REQ_DEVSET_EXEC:
345 return ide_do_devset(drive, rq);
346 case REQ_DRIVE_RESET:
347 return ide_do_reset(drive);
349 blk_dump_rq_flags(rq, "ide_special_rq - bad request");
350 ide_end_request(drive, 0, 0);
356 * start_request - start of I/O and command issuing for IDE
358 * start_request() initiates handling of a new I/O request. It
359 * accepts commands and I/O (read/write) requests.
361 * FIXME: this function needs a rename
364 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
366 ide_startstop_t startstop;
368 BUG_ON(!blk_rq_started(rq));
371 printk("%s: start_request: current=0x%08lx\n",
372 drive->hwif->name, (unsigned long) rq);
375 /* bail early if we've exceeded max_failures */
376 if (drive->max_failures && (drive->failures > drive->max_failures)) {
377 rq->cmd_flags |= REQ_FAILED;
381 if (blk_pm_request(rq))
382 ide_check_pm_state(drive, rq);
385 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
386 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
387 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
390 if (!drive->special.all) {
391 struct ide_driver *drv;
394 * We reset the drive so we need to issue a SETFEATURES.
395 * Do it _after_ do_special() restored device parameters.
397 if (drive->current_speed == 0xff)
398 ide_config_drive_speed(drive, drive->desired_speed);
400 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
401 return execute_drive_cmd(drive, rq);
402 else if (blk_pm_request(rq)) {
403 struct request_pm_state *pm = rq->data;
405 printk("%s: start_power_step(step: %d)\n",
406 drive->name, pm->pm_step);
408 startstop = ide_start_power_step(drive, rq);
409 if (startstop == ide_stopped &&
410 pm->pm_step == IDE_PM_COMPLETED)
411 ide_complete_pm_rq(drive, rq);
413 } else if (!rq->rq_disk && blk_special_request(rq))
415 * TODO: Once all ULDs have been modified to
416 * check for specific op codes rather than
417 * blindly accepting any special request, the
418 * check for ->rq_disk above may be replaced
419 * by a more suitable mechanism or even
422 return ide_special_rq(drive, rq);
424 drv = *(struct ide_driver **)rq->rq_disk->private_data;
426 return drv->do_request(drive, rq, rq->sector);
428 return do_special(drive);
430 ide_kill_rq(drive, rq);
435 * ide_stall_queue - pause an IDE device
436 * @drive: drive to stall
437 * @timeout: time to stall for (jiffies)
439 * ide_stall_queue() can be used by a drive to give excess bandwidth back
440 * to the port by sleeping for timeout jiffies.
443 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
445 if (timeout > WAIT_WORSTCASE)
446 timeout = WAIT_WORSTCASE;
447 drive->sleep = timeout + jiffies;
448 drive->dev_flags |= IDE_DFLAG_SLEEPING;
450 EXPORT_SYMBOL(ide_stall_queue);
452 static inline int ide_lock_port(ide_hwif_t *hwif)
462 static inline void ide_unlock_port(ide_hwif_t *hwif)
467 static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
471 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
472 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
475 host->get_lock(ide_intr, hwif);
481 static inline void ide_unlock_host(struct ide_host *host)
483 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
484 if (host->release_lock)
485 host->release_lock();
486 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
491 * Issue a new request to a device.
493 void do_ide_request(struct request_queue *q)
495 ide_drive_t *drive = q->queuedata;
496 ide_hwif_t *hwif = drive->hwif;
497 struct ide_host *host = hwif->host;
498 struct request *rq = NULL;
499 ide_startstop_t startstop;
502 * drive is doing pre-flush, ordered write, post-flush sequence. even
503 * though that is 3 requests, it must be seen as a single transaction.
504 * we must not preempt this drive until that is complete
506 if (blk_queue_flushing(q))
508 * small race where queue could get replugged during
509 * the 3-request flush cycle, just yank the plug since
510 * we want it to finish asap
514 spin_unlock_irq(q->queue_lock);
516 if (ide_lock_host(host, hwif))
519 spin_lock_irq(&hwif->lock);
521 if (!ide_lock_port(hwif)) {
522 ide_hwif_t *prev_port;
524 prev_port = hwif->host->cur_port;
527 if (drive->dev_flags & IDE_DFLAG_SLEEPING) {
528 if (time_before(drive->sleep, jiffies)) {
529 ide_unlock_port(hwif);
534 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
537 * set nIEN for previous port, drives in the
538 * quirk_list may not like intr setups/cleanups
540 if (prev_port && prev_port->cur_dev->quirk_list == 0)
541 prev_port->tp_ops->set_irq(prev_port, 0);
543 hwif->host->cur_port = hwif;
545 hwif->cur_dev = drive;
546 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
548 spin_unlock_irq(&hwif->lock);
549 spin_lock_irq(q->queue_lock);
551 * we know that the queue isn't empty, but this can happen
552 * if the q->prep_rq_fn() decides to kill a request
554 rq = elv_next_request(drive->queue);
555 spin_unlock_irq(q->queue_lock);
556 spin_lock_irq(&hwif->lock);
559 ide_unlock_port(hwif);
564 * Sanity: don't accept a request that isn't a PM request
565 * if we are currently power managed. This is very important as
566 * blk_stop_queue() doesn't prevent the elv_next_request()
567 * above to return us whatever is in the queue. Since we call
568 * ide_do_request() ourselves, we end up taking requests while
569 * the queue is blocked...
571 * We let requests forced at head of queue with ide-preempt
572 * though. I hope that doesn't happen too much, hopefully not
573 * unless the subdriver triggers such a thing in its own PM
576 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
577 blk_pm_request(rq) == 0 &&
578 (rq->cmd_flags & REQ_PREEMPT) == 0) {
579 /* there should be no pending command at this point */
580 ide_unlock_port(hwif);
586 spin_unlock_irq(&hwif->lock);
587 startstop = start_request(drive, rq);
588 spin_lock_irq(&hwif->lock);
590 if (startstop == ide_stopped)
595 spin_unlock_irq(&hwif->lock);
597 ide_unlock_host(host);
598 spin_lock_irq(q->queue_lock);
602 spin_unlock_irq(&hwif->lock);
603 ide_unlock_host(host);
605 spin_lock_irq(q->queue_lock);
607 if (!elv_queue_empty(q))
611 static void ide_plug_device(ide_drive_t *drive)
613 struct request_queue *q = drive->queue;
616 spin_lock_irqsave(q->queue_lock, flags);
617 if (!elv_queue_empty(q))
619 spin_unlock_irqrestore(q->queue_lock, flags);
622 static int drive_is_ready(ide_drive_t *drive)
624 ide_hwif_t *hwif = drive->hwif;
627 if (drive->waiting_for_dma)
628 return hwif->dma_ops->dma_test_irq(drive);
630 if (hwif->io_ports.ctl_addr &&
631 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
632 stat = hwif->tp_ops->read_altstatus(hwif);
634 /* Note: this may clear a pending IRQ!! */
635 stat = hwif->tp_ops->read_status(hwif);
638 /* drive busy: definitely not interrupting */
641 /* drive ready: *might* be interrupting */
646 * ide_timer_expiry - handle lack of an IDE interrupt
647 * @data: timer callback magic (hwif)
649 * An IDE command has timed out before the expected drive return
650 * occurred. At this point we attempt to clean up the current
651 * mess. If the current handler includes an expiry handler then
652 * we invoke the expiry handler, and providing it is happy the
653 * work is done. If that fails we apply generic recovery rules
654 * invoking the handler and checking the drive DMA status. We
655 * have an excessively incestuous relationship with the DMA
656 * logic that wants cleaning up.
659 void ide_timer_expiry (unsigned long data)
661 ide_hwif_t *hwif = (ide_hwif_t *)data;
662 ide_drive_t *uninitialized_var(drive);
663 ide_handler_t *handler;
668 spin_lock_irqsave(&hwif->lock, flags);
670 handler = hwif->handler;
672 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
674 * Either a marginal timeout occurred
675 * (got the interrupt just as timer expired),
676 * or we were "sleeping" to give other devices a chance.
677 * Either way, we don't really want to complain about anything.
680 ide_expiry_t *expiry = hwif->expiry;
681 ide_startstop_t startstop = ide_stopped;
683 drive = hwif->cur_dev;
686 wait = expiry(drive);
687 if (wait > 0) { /* continue */
689 hwif->timer.expires = jiffies + wait;
690 hwif->req_gen_timer = hwif->req_gen;
691 add_timer(&hwif->timer);
692 spin_unlock_irqrestore(&hwif->lock, flags);
696 hwif->handler = NULL;
698 * We need to simulate a real interrupt when invoking
699 * the handler() function, which means we need to
700 * globally mask the specific IRQ:
702 spin_unlock(&hwif->lock);
703 /* disable_irq_nosync ?? */
704 disable_irq(hwif->irq);
705 /* local CPU only, as if we were handling an interrupt */
708 startstop = handler(drive);
709 } else if (drive_is_ready(drive)) {
710 if (drive->waiting_for_dma)
711 hwif->dma_ops->dma_lost_irq(drive);
713 hwif->ack_intr(hwif);
714 printk(KERN_WARNING "%s: lost interrupt\n",
716 startstop = handler(drive);
718 if (drive->waiting_for_dma)
719 startstop = ide_dma_timeout_retry(drive, wait);
721 startstop = ide_error(drive, "irq timeout",
722 hwif->tp_ops->read_status(hwif));
724 spin_lock_irq(&hwif->lock);
725 enable_irq(hwif->irq);
726 if (startstop == ide_stopped) {
727 ide_unlock_port(hwif);
731 spin_unlock_irqrestore(&hwif->lock, flags);
734 ide_unlock_host(hwif->host);
735 ide_plug_device(drive);
740 * unexpected_intr - handle an unexpected IDE interrupt
741 * @irq: interrupt line
742 * @hwif: port being processed
744 * There's nothing really useful we can do with an unexpected interrupt,
745 * other than reading the status register (to clear it), and logging it.
746 * There should be no way that an irq can happen before we're ready for it,
747 * so we needn't worry much about losing an "important" interrupt here.
749 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
750 * the drive enters "idle", "standby", or "sleep" mode, so if the status
751 * looks "good", we just ignore the interrupt completely.
753 * This routine assumes __cli() is in effect when called.
755 * If an unexpected interrupt happens on irq15 while we are handling irq14
756 * and if the two interfaces are "serialized" (CMD640), then it looks like
757 * we could screw up by interfering with a new request being set up for
760 * In reality, this is a non-issue. The new command is not sent unless
761 * the drive is ready to accept one, in which case we know the drive is
762 * not trying to interrupt us. And ide_set_handler() is always invoked
763 * before completing the issuance of any new drive command, so we will not
764 * be accidentally invoked as a result of any valid command completion
768 static void unexpected_intr(int irq, ide_hwif_t *hwif)
770 u8 stat = hwif->tp_ops->read_status(hwif);
772 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
773 /* Try to not flood the console with msgs */
774 static unsigned long last_msgtime, count;
777 if (time_after(jiffies, last_msgtime + HZ)) {
778 last_msgtime = jiffies;
779 printk(KERN_ERR "%s: unexpected interrupt, "
780 "status=0x%02x, count=%ld\n",
781 hwif->name, stat, count);
787 * ide_intr - default IDE interrupt handler
788 * @irq: interrupt number
790 * @regs: unused weirdness from the kernel irq layer
792 * This is the default IRQ handler for the IDE layer. You should
793 * not need to override it. If you do be aware it is subtle in
796 * hwif is the interface in the group currently performing
797 * a command. hwif->cur_dev is the drive and hwif->handler is
798 * the IRQ handler to call. As we issue a command the handlers
799 * step through multiple states, reassigning the handler to the
800 * next step in the process. Unlike a smart SCSI controller IDE
801 * expects the main processor to sequence the various transfer
802 * stages. We also manage a poll timer to catch up with most
803 * timeout situations. There are still a few where the handlers
804 * don't ever decide to give up.
806 * The handler eventually returns ide_stopped to indicate the
807 * request completed. At this point we issue the next request
808 * on the port and the process begins again.
811 irqreturn_t ide_intr (int irq, void *dev_id)
813 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
814 struct ide_host *host = hwif->host;
815 ide_drive_t *uninitialized_var(drive);
816 ide_handler_t *handler;
818 ide_startstop_t startstop;
819 irqreturn_t irq_ret = IRQ_NONE;
822 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
823 if (hwif != host->cur_port)
827 spin_lock_irqsave(&hwif->lock, flags);
829 if (hwif->ack_intr && hwif->ack_intr(hwif) == 0)
832 handler = hwif->handler;
834 if (handler == NULL || hwif->polling) {
836 * Not expecting an interrupt from this drive.
837 * That means this could be:
838 * (1) an interrupt from another PCI device
839 * sharing the same PCI INT# as us.
840 * or (2) a drive just entered sleep or standby mode,
841 * and is interrupting to let us know.
842 * or (3) a spurious interrupt of unknown origin.
844 * For PCI, we cannot tell the difference,
845 * so in that case we just ignore it and hope it goes away.
847 if ((host->irq_flags & IRQF_SHARED) == 0) {
849 * Probably not a shared PCI interrupt,
850 * so we can safely try to do something about it:
852 unexpected_intr(irq, hwif);
855 * Whack the status register, just in case
856 * we have a leftover pending IRQ.
858 (void)hwif->tp_ops->read_status(hwif);
863 drive = hwif->cur_dev;
865 if (!drive_is_ready(drive))
867 * This happens regularly when we share a PCI IRQ with
868 * another device. Unfortunately, it can also happen
869 * with some buggy drives that trigger the IRQ before
870 * their status register is up to date. Hopefully we have
871 * enough advance overhead that the latter isn't a problem.
875 hwif->handler = NULL;
877 del_timer(&hwif->timer);
878 spin_unlock(&hwif->lock);
880 if (hwif->port_ops && hwif->port_ops->clear_irq)
881 hwif->port_ops->clear_irq(drive);
883 if (drive->dev_flags & IDE_DFLAG_UNMASK)
884 local_irq_enable_in_hardirq();
886 /* service this interrupt, may set handler for next interrupt */
887 startstop = handler(drive);
889 spin_lock_irq(&hwif->lock);
891 * Note that handler() may have set things up for another
892 * interrupt to occur soon, but it cannot happen until
893 * we exit from this routine, because it will be the
894 * same irq as is currently being serviced here, and Linux
895 * won't allow another of the same (on any CPU) until we return.
897 if (startstop == ide_stopped) {
898 BUG_ON(hwif->handler);
899 ide_unlock_port(hwif);
902 irq_ret = IRQ_HANDLED;
904 spin_unlock_irqrestore(&hwif->lock, flags);
907 ide_unlock_host(hwif->host);
908 ide_plug_device(drive);
913 EXPORT_SYMBOL_GPL(ide_intr);
915 void ide_pad_transfer(ide_drive_t *drive, int write, int len)
917 ide_hwif_t *hwif = drive->hwif;
922 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
924 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
928 EXPORT_SYMBOL_GPL(ide_pad_transfer);