drivers/ide/ide-eh.c - fs/xfs/xfs-linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only

 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/ide.h>
 #include <linux/delay.h>

 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 				     u8 stat, u8 err)
 {
 	ide_hwif_t *hwif = drive->hwif;

 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
 		scsi_req(rq)->result |= ERROR_RESET;
 	} else if (stat & ATA_ERR) {
 		/* err has different meaning on cdrom and tape */
 		if (err == ATA_ABORTED) {
 			if ((drive->dev_flags & IDE_DFLAG_LBA) &&
 			    /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */
 			    hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS)
 				return ide_stopped;
 		} else if ((err & BAD_CRC) == BAD_CRC) {
 			/* UDMA crc error, just retry the operation */
 			drive->crc_count++;
 		} else if (err & (ATA_BBK | ATA_UNC)) {
 			/* retries won't help these */
 			scsi_req(rq)->result = ERROR_MAX;
 		} else if (err & ATA_TRK0NF) {
 			/* help it find track zero */
 			scsi_req(rq)->result |= ERROR_RECAL;
 		}
 	}

 	if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ &&
 	    (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) {
 		int nsect = drive->mult_count ? drive->mult_count : 1;

 		ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
 	}

 	if (scsi_req(rq)->result >= ERROR_MAX || blk_noretry_request(rq)) {
 		ide_kill_rq(drive, rq);
 		return ide_stopped;
 	}

 	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
 		scsi_req(rq)->result |= ERROR_RESET;

 	if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
 		++scsi_req(rq)->result;
 		return ide_do_reset(drive);
 	}

 	if ((scsi_req(rq)->result & ERROR_RECAL) == ERROR_RECAL)
 		drive->special_flags |= IDE_SFLAG_RECALIBRATE;

 	++scsi_req(rq)->result;

 	return ide_stopped;
 }

 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
 				       u8 stat, u8 err)
 {
 	ide_hwif_t *hwif = drive->hwif;

 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
 		scsi_req(rq)->result |= ERROR_RESET;
 	} else {
 		/* add decoding error stuff */
 	}

 	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
 		/* force an abort */
 		hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);

 	if (scsi_req(rq)->result >= ERROR_MAX) {
 		ide_kill_rq(drive, rq);
 	} else {
 		if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
 			++scsi_req(rq)->result;
 			return ide_do_reset(drive);
 		}
 		++scsi_req(rq)->result;
 	}

 	return ide_stopped;
 }

 static ide_startstop_t __ide_error(ide_drive_t *drive, struct request *rq,
 				   u8 stat, u8 err)
 {
 	if (drive->media == ide_disk)
 		return ide_ata_error(drive, rq, stat, err);
 	return ide_atapi_error(drive, rq, stat, err);
 }

 /**
  *	ide_error	-	handle an error on the IDE
  *	@drive: drive the error occurred on
  *	@msg: message to report
  *	@stat: status bits
  *
  *	ide_error() takes action based on the error returned by the drive.
  *	For normal I/O that may well include retries. We deal with
  *	both new-style (taskfile) and old style command handling here.
  *	In the case of taskfile command handling there is work left to
  *	do
  */

 ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
 {
 	struct request *rq;
 	u8 err;

 	err = ide_dump_status(drive, msg, stat);

 	rq = drive->hwif->rq;
 	if (rq == NULL)
 		return ide_stopped;

 	/* retry only "normal" I/O: */
 	if (blk_rq_is_passthrough(rq)) {
 		if (ata_taskfile_request(rq)) {
 			struct ide_cmd *cmd = ide_req(rq)->special;

 			if (cmd)
 				ide_complete_cmd(drive, cmd, stat, err);
 		} else if (ata_pm_request(rq)) {
 			scsi_req(rq)->result = 1;
 			ide_complete_pm_rq(drive, rq);
 			return ide_stopped;
 		}
 		scsi_req(rq)->result = err;
 		ide_complete_rq(drive, err ? BLK_STS_IOERR : BLK_STS_OK, blk_rq_bytes(rq));
 		return ide_stopped;
 	}

 	return __ide_error(drive, rq, stat, err);
 }
 EXPORT_SYMBOL_GPL(ide_error);

 static inline void ide_complete_drive_reset(ide_drive_t *drive, blk_status_t err)
 {
 	struct request *rq = drive->hwif->rq;

 	if (rq && ata_misc_request(rq) &&
 	    scsi_req(rq)->cmd[0] == REQ_DRIVE_RESET) {
 		if (err <= 0 && scsi_req(rq)->result == 0)
 			scsi_req(rq)->result = -EIO;
 		ide_complete_rq(drive, err, blk_rq_bytes(rq));
 	}
 }

 /* needed below */
 static ide_startstop_t do_reset1(ide_drive_t *, int);

 /*
  * atapi_reset_pollfunc() gets invoked to poll the interface for completion
  * every 50ms during an atapi drive reset operation.  If the drive has not yet
  * responded, and we have not yet hit our maximum waiting time, then the timer
  * is restarted for another 50ms.
  */
 static ide_startstop_t atapi_reset_pollfunc(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 	u8 stat;

 	tp_ops->dev_select(drive);
 	udelay(10);
 	stat = tp_ops->read_status(hwif);

 	if (OK_STAT(stat, 0, ATA_BUSY))
 		printk(KERN_INFO "%s: ATAPI reset complete\n", drive->name);
 	else {
 		if (time_before(jiffies, hwif->poll_timeout)) {
 			ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20);
 			/* continue polling */
 			return ide_started;
 		}
 		/* end of polling */
 		hwif->polling = 0;
 		printk(KERN_ERR "%s: ATAPI reset timed-out, status=0x%02x\n",
 			drive->name, stat);
 		/* do it the old fashioned way */
 		return do_reset1(drive, 1);
 	}
 	/* done polling */
 	hwif->polling = 0;
 	ide_complete_drive_reset(drive, BLK_STS_OK);
 	return ide_stopped;
 }

 static void ide_reset_report_error(ide_hwif_t *hwif, u8 err)
 {
 	static const char *err_master_vals[] =
 		{ NULL, "passed", "formatter device error",
 		  "sector buffer error", "ECC circuitry error",
 		  "controlling MPU error" };

 	u8 err_master = err & 0x7f;

 	printk(KERN_ERR "%s: reset: master: ", hwif->name);
 	if (err_master && err_master < 6)
 		printk(KERN_CONT "%s", err_master_vals[err_master]);
 	else
 		printk(KERN_CONT "error (0x%02x?)", err);
 	if (err & 0x80)
 		printk(KERN_CONT "; slave: failed");
 	printk(KERN_CONT "\n");
 }

 /*
  * reset_pollfunc() gets invoked to poll the interface for completion every 50ms
  * during an ide reset operation. If the drives have not yet responded,
  * and we have not yet hit our maximum waiting time, then the timer is restarted
  * for another 50ms.
  */
 static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	const struct ide_port_ops *port_ops = hwif->port_ops;
 	u8 tmp;
 	blk_status_t err = BLK_STS_OK;

 	if (port_ops && port_ops->reset_poll) {
 		err = port_ops->reset_poll(drive);
 		if (err) {
 			printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
 				hwif->name, drive->name);
 			goto out;
 		}
 	}

 	tmp = hwif->tp_ops->read_status(hwif);

 	if (!OK_STAT(tmp, 0, ATA_BUSY)) {
 		if (time_before(jiffies, hwif->poll_timeout)) {
 			ide_set_handler(drive, &reset_pollfunc, HZ/20);
 			/* continue polling */
 			return ide_started;
 		}
 		printk(KERN_ERR "%s: reset timed-out, status=0x%02x\n",
 			hwif->name, tmp);
 		drive->failures++;
 		err = BLK_STS_IOERR;
 	} else  {
 		tmp = ide_read_error(drive);

 		if (tmp == 1) {
 			printk(KERN_INFO "%s: reset: success\n", hwif->name);
 			drive->failures = 0;
 		} else {
 			ide_reset_report_error(hwif, tmp);
 			drive->failures++;
 			err = BLK_STS_IOERR;
 		}
 	}
 out:
 	hwif->polling = 0;	/* done polling */
 	ide_complete_drive_reset(drive, err);
 	return ide_stopped;
 }

 static void ide_disk_pre_reset(ide_drive_t *drive)
 {
 	int legacy = (drive->id[ATA_ID_CFS_ENABLE_2] & 0x0400) ? 0 : 1;

 	drive->special_flags =
 		legacy ? (IDE_SFLAG_SET_GEOMETRY | IDE_SFLAG_RECALIBRATE) : 0;

 	drive->mult_count = 0;
 	drive->dev_flags &= ~IDE_DFLAG_PARKED;

 	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0 &&
 	    (drive->dev_flags & IDE_DFLAG_USING_DMA) == 0)
 		drive->mult_req = 0;

 	if (drive->mult_req != drive->mult_count)
 		drive->special_flags |= IDE_SFLAG_SET_MULTMODE;
 }

 static void pre_reset(ide_drive_t *drive)
 {
 	const struct ide_port_ops *port_ops = drive->hwif->port_ops;

 	if (drive->media == ide_disk)
 		ide_disk_pre_reset(drive);
 	else
 		drive->dev_flags |= IDE_DFLAG_POST_RESET;

 	if (drive->dev_flags & IDE_DFLAG_USING_DMA) {
 		if (drive->crc_count)
 			ide_check_dma_crc(drive);
 		else
 			ide_dma_off(drive);
 	}

 	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0) {
 		if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0) {
 			drive->dev_flags &= ~IDE_DFLAG_UNMASK;
 			drive->io_32bit = 0;
 		}
 		return;
 	}

 	if (port_ops && port_ops->pre_reset)
 		port_ops->pre_reset(drive);

 	if (drive->current_speed != 0xff)
 		drive->desired_speed = drive->current_speed;
 	drive->current_speed = 0xff;
 }

 /*
  * do_reset1() attempts to recover a confused drive by resetting it.
  * Unfortunately, resetting a disk drive actually resets all devices on
  * the same interface, so it can really be thought of as resetting the
  * interface rather than resetting the drive.
  *
  * ATAPI devices have their own reset mechanism which allows them to be
  * individually reset without clobbering other devices on the same interface.
  *
  * Unfortunately, the IDE interface does not generate an interrupt to let
  * us know when the reset operation has finished, so we must poll for this.
  * Equally poor, though, is the fact that this may a very long time to complete,
  * (up to 30 seconds worstcase).  So, instead of busy-waiting here for it,
  * we set a timer to poll at 50ms intervals.
  */
 static ide_startstop_t do_reset1(ide_drive_t *drive, int do_not_try_atapi)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	struct ide_io_ports *io_ports = &hwif->io_ports;
 	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
 	const struct ide_port_ops *port_ops;
 	ide_drive_t *tdrive;
 	unsigned long flags, timeout;
 	int i;
 	DEFINE_WAIT(wait);

 	spin_lock_irqsave(&hwif->lock, flags);

 	/* We must not reset with running handlers */
 	BUG_ON(hwif->handler != NULL);

 	/* For an ATAPI device, first try an ATAPI SRST. */
 	if (drive->media != ide_disk && !do_not_try_atapi) {
 		pre_reset(drive);
 		tp_ops->dev_select(drive);
 		udelay(20);
 		tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
 		ndelay(400);
 		hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
 		hwif->polling = 1;
 		__ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20);
 		spin_unlock_irqrestore(&hwif->lock, flags);
 		return ide_started;
 	}

 	/* We must not disturb devices in the IDE_DFLAG_PARKED state. */
 	do {
 		unsigned long now;

 		prepare_to_wait(&ide_park_wq, &wait, TASK_UNINTERRUPTIBLE);
 		timeout = jiffies;
 		ide_port_for_each_present_dev(i, tdrive, hwif) {
 			if ((tdrive->dev_flags & IDE_DFLAG_PARKED) &&
 			    time_after(tdrive->sleep, timeout))
 				timeout = tdrive->sleep;
 		}

 		now = jiffies;
 		if (time_before_eq(timeout, now))
 			break;

 		spin_unlock_irqrestore(&hwif->lock, flags);
 		timeout = schedule_timeout_uninterruptible(timeout - now);
 		spin_lock_irqsave(&hwif->lock, flags);
 	} while (timeout);
 	finish_wait(&ide_park_wq, &wait);

 	/*
 	 * First, reset any device state data we were maintaining
 	 * for any of the drives on this interface.
 	 */
 	ide_port_for_each_dev(i, tdrive, hwif)
 		pre_reset(tdrive);

 	if (io_ports->ctl_addr == 0) {
 		spin_unlock_irqrestore(&hwif->lock, flags);
 		ide_complete_drive_reset(drive, BLK_STS_IOERR);
 		return ide_stopped;
 	}

 	/*
 	 * Note that we also set nIEN while resetting the device,
 	 * to mask unwanted interrupts from the interface during the reset.
 	 * However, due to the design of PC hardware, this will cause an
 	 * immediate interrupt due to the edge transition it produces.
 	 * This single interrupt gives us a "fast poll" for drives that
 	 * recover from reset very quickly, saving us the first 50ms wait time.
 	 */
 	/* set SRST and nIEN */
 	tp_ops->write_devctl(hwif, ATA_SRST | ATA_NIEN | ATA_DEVCTL_OBS);
 	/* more than enough time */
 	udelay(10);
 	/* clear SRST, leave nIEN (unless device is on the quirk list) */
 	tp_ops->write_devctl(hwif,
 		((drive->dev_flags & IDE_DFLAG_NIEN_QUIRK) ? 0 : ATA_NIEN) |
 		 ATA_DEVCTL_OBS);
 	/* more than enough time */
 	udelay(10);
 	hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
 	hwif->polling = 1;
 	__ide_set_handler(drive, &reset_pollfunc, HZ/20);

 	/*
 	 * Some weird controller like resetting themselves to a strange
 	 * state when the disks are reset this way. At least, the Winbond
 	 * 553 documentation says that
 	 */
 	port_ops = hwif->port_ops;
 	if (port_ops && port_ops->resetproc)
 		port_ops->resetproc(drive);

 	spin_unlock_irqrestore(&hwif->lock, flags);
 	return ide_started;
 }

 /*
  * ide_do_reset() is the entry point to the drive/interface reset code.
  */

 ide_startstop_t ide_do_reset(ide_drive_t *drive)
 {
 	return do_reset1(drive, 0);
 }
 EXPORT_SYMBOL(ide_do_reset);
	// SPDX-License-Identifier: GPL-2.0-only

	#include <linux/kernel.h>
	#include <linux/export.h>
	#include <linux/ide.h>
	#include <linux/delay.h>

	static ide_startstop_t ide_ata_error(ide_drive_t drive, struct request rq,
	u8 stat, u8 err)
	{
	ide_hwif_t *hwif = drive->hwif;

	if ((stat & ATA_BUSY) \|\|
	((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
	/* other bits are useless when BUSY */
	scsi_req(rq)->result \|= ERROR_RESET;
	} else if (stat & ATA_ERR) {
	/* err has different meaning on cdrom and tape */
	if (err == ATA_ABORTED) {
	if ((drive->dev_flags & IDE_DFLAG_LBA) &&
	/* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */
	hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS)
	return ide_stopped;
	} else if ((err & BAD_CRC) == BAD_CRC) {
	/* UDMA crc error, just retry the operation */
	drive->crc_count++;
	} else if (err & (ATA_BBK \| ATA_UNC)) {
	/* retries won't help these */
	scsi_req(rq)->result = ERROR_MAX;
	} else if (err & ATA_TRK0NF) {
	/* help it find track zero */
	scsi_req(rq)->result \|= ERROR_RECAL;
	}
	}

	if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ &&
	(hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) {
	int nsect = drive->mult_count ? drive->mult_count : 1;

	ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
	}

	if (scsi_req(rq)->result >= ERROR_MAX \|\| blk_noretry_request(rq)) {
	ide_kill_rq(drive, rq);
	return ide_stopped;
	}

	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY \| ATA_DRQ))
	scsi_req(rq)->result \|= ERROR_RESET;

	if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
	++scsi_req(rq)->result;
	return ide_do_reset(drive);
	}

	if ((scsi_req(rq)->result & ERROR_RECAL) == ERROR_RECAL)
	drive->special_flags \|= IDE_SFLAG_RECALIBRATE;

	++scsi_req(rq)->result;

	return ide_stopped;
	}

	static ide_startstop_t ide_atapi_error(ide_drive_t drive, struct request rq,
	u8 stat, u8 err)
	{
	ide_hwif_t *hwif = drive->hwif;

	if ((stat & ATA_BUSY) \|\|
	((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
	/* other bits are useless when BUSY */
	scsi_req(rq)->result \|= ERROR_RESET;
	} else {
	/* add decoding error stuff */
	}

	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY \| ATA_DRQ))
	/* force an abort */
	hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);

	if (scsi_req(rq)->result >= ERROR_MAX) {
	ide_kill_rq(drive, rq);
	} else {
	if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
	++scsi_req(rq)->result;
	return ide_do_reset(drive);
	}
	++scsi_req(rq)->result;
	}

	return ide_stopped;
	}

	static ide_startstop_t __ide_error(ide_drive_t drive, struct request rq,
	u8 stat, u8 err)
	{
	if (drive->media == ide_disk)
	return ide_ata_error(drive, rq, stat, err);
	return ide_atapi_error(drive, rq, stat, err);
	}

	/**
	* ide_error - handle an error on the IDE
	* @drive: drive the error occurred on
	* @msg: message to report
	* @stat: status bits
	*
	* ide_error() takes action based on the error returned by the drive.
	* For normal I/O that may well include retries. We deal with
	* both new-style (taskfile) and old style command handling here.
	* In the case of taskfile command handling there is work left to
	* do
	*/

	ide_startstop_t ide_error(ide_drive_t drive, const char msg, u8 stat)
	{
	struct request *rq;
	u8 err;

	err = ide_dump_status(drive, msg, stat);

	rq = drive->hwif->rq;
	if (rq == NULL)
	return ide_stopped;

	/* retry only "normal" I/O: */
	if (blk_rq_is_passthrough(rq)) {
	if (ata_taskfile_request(rq)) {
	struct ide_cmd *cmd = ide_req(rq)->special;

	if (cmd)
	ide_complete_cmd(drive, cmd, stat, err);
	} else if (ata_pm_request(rq)) {
	scsi_req(rq)->result = 1;
	ide_complete_pm_rq(drive, rq);
	return ide_stopped;
	}
	scsi_req(rq)->result = err;
	ide_complete_rq(drive, err ? BLK_STS_IOERR : BLK_STS_OK, blk_rq_bytes(rq));
	return ide_stopped;
	}

	return __ide_error(drive, rq, stat, err);
	}
	EXPORT_SYMBOL_GPL(ide_error);

	static inline void ide_complete_drive_reset(ide_drive_t *drive, blk_status_t err)
	{
	struct request *rq = drive->hwif->rq;

	if (rq && ata_misc_request(rq) &&
	scsi_req(rq)->cmd[0] == REQ_DRIVE_RESET) {
	if (err <= 0 && scsi_req(rq)->result == 0)
	scsi_req(rq)->result = -EIO;
	ide_complete_rq(drive, err, blk_rq_bytes(rq));
	}
	}

	/* needed below */
	static ide_startstop_t do_reset1(ide_drive_t *, int);

	/*
	* atapi_reset_pollfunc() gets invoked to poll the interface for completion
	* every 50ms during an atapi drive reset operation. If the drive has not yet
	* responded, and we have not yet hit our maximum waiting time, then the timer
	* is restarted for another 50ms.
	*/
	static ide_startstop_t atapi_reset_pollfunc(ide_drive_t *drive)
	{
	ide_hwif_t *hwif = drive->hwif;
	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
	u8 stat;

	tp_ops->dev_select(drive);
	udelay(10);
	stat = tp_ops->read_status(hwif);

	if (OK_STAT(stat, 0, ATA_BUSY))
	printk(KERN_INFO "%s: ATAPI reset complete\n", drive->name);
	else {
	if (time_before(jiffies, hwif->poll_timeout)) {
	ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20);
	/* continue polling */
	return ide_started;
	}
	/* end of polling */
	hwif->polling = 0;
	printk(KERN_ERR "%s: ATAPI reset timed-out, status=0x%02x\n",
	drive->name, stat);
	/* do it the old fashioned way */
	return do_reset1(drive, 1);
	}
	/* done polling */
	hwif->polling = 0;
	ide_complete_drive_reset(drive, BLK_STS_OK);
	return ide_stopped;
	}

	static void ide_reset_report_error(ide_hwif_t *hwif, u8 err)
	{
	static const char *err_master_vals[] =
	{ NULL, "passed", "formatter device error",
	"sector buffer error", "ECC circuitry error",
	"controlling MPU error" };

	u8 err_master = err & 0x7f;

	printk(KERN_ERR "%s: reset: master: ", hwif->name);
	if (err_master && err_master < 6)
	printk(KERN_CONT "%s", err_master_vals[err_master]);
	else
	printk(KERN_CONT "error (0x%02x?)", err);
	if (err & 0x80)
	printk(KERN_CONT "; slave: failed");
	printk(KERN_CONT "\n");
	}

	/*
	* reset_pollfunc() gets invoked to poll the interface for completion every 50ms
	* during an ide reset operation. If the drives have not yet responded,
	* and we have not yet hit our maximum waiting time, then the timer is restarted
	* for another 50ms.
	*/
	static ide_startstop_t reset_pollfunc(ide_drive_t *drive)
	{
	ide_hwif_t *hwif = drive->hwif;
	const struct ide_port_ops *port_ops = hwif->port_ops;
	u8 tmp;
	blk_status_t err = BLK_STS_OK;

	if (port_ops && port_ops->reset_poll) {
	err = port_ops->reset_poll(drive);
	if (err) {
	printk(KERN_ERR "%s: host reset_poll failure for %s.\n",
	hwif->name, drive->name);
	goto out;
	}
	}

	tmp = hwif->tp_ops->read_status(hwif);

	if (!OK_STAT(tmp, 0, ATA_BUSY)) {
	if (time_before(jiffies, hwif->poll_timeout)) {
	ide_set_handler(drive, &reset_pollfunc, HZ/20);
	/* continue polling */
	return ide_started;
	}
	printk(KERN_ERR "%s: reset timed-out, status=0x%02x\n",
	hwif->name, tmp);
	drive->failures++;
	err = BLK_STS_IOERR;
	} else {
	tmp = ide_read_error(drive);

	if (tmp == 1) {
	printk(KERN_INFO "%s: reset: success\n", hwif->name);
	drive->failures = 0;
	} else {
	ide_reset_report_error(hwif, tmp);
	drive->failures++;
	err = BLK_STS_IOERR;
	}
	}
	out:
	hwif->polling = 0; /* done polling */
	ide_complete_drive_reset(drive, err);
	return ide_stopped;
	}

	static void ide_disk_pre_reset(ide_drive_t *drive)
	{
	int legacy = (drive->id[ATA_ID_CFS_ENABLE_2] & 0x0400) ? 0 : 1;

	drive->special_flags =
	legacy ? (IDE_SFLAG_SET_GEOMETRY \| IDE_SFLAG_RECALIBRATE) : 0;

	drive->mult_count = 0;
	drive->dev_flags &= ~IDE_DFLAG_PARKED;

	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0 &&
	(drive->dev_flags & IDE_DFLAG_USING_DMA) == 0)
	drive->mult_req = 0;

	if (drive->mult_req != drive->mult_count)
	drive->special_flags \|= IDE_SFLAG_SET_MULTMODE;
	}

	static void pre_reset(ide_drive_t *drive)
	{
	const struct ide_port_ops *port_ops = drive->hwif->port_ops;

	if (drive->media == ide_disk)
	ide_disk_pre_reset(drive);
	else
	drive->dev_flags \|= IDE_DFLAG_POST_RESET;

	if (drive->dev_flags & IDE_DFLAG_USING_DMA) {
	if (drive->crc_count)
	ide_check_dma_crc(drive);
	else
	ide_dma_off(drive);
	}

	if ((drive->dev_flags & IDE_DFLAG_KEEP_SETTINGS) == 0) {
	if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0) {
	drive->dev_flags &= ~IDE_DFLAG_UNMASK;
	drive->io_32bit = 0;
	}
	return;
	}

	if (port_ops && port_ops->pre_reset)
	port_ops->pre_reset(drive);

	if (drive->current_speed != 0xff)
	drive->desired_speed = drive->current_speed;
	drive->current_speed = 0xff;
	}

	/*
	* do_reset1() attempts to recover a confused drive by resetting it.
	* Unfortunately, resetting a disk drive actually resets all devices on
	* the same interface, so it can really be thought of as resetting the
	* interface rather than resetting the drive.
	*
	* ATAPI devices have their own reset mechanism which allows them to be
	* individually reset without clobbering other devices on the same interface.
	*
	* Unfortunately, the IDE interface does not generate an interrupt to let
	* us know when the reset operation has finished, so we must poll for this.
	* Equally poor, though, is the fact that this may a very long time to complete,
	* (up to 30 seconds worstcase). So, instead of busy-waiting here for it,
	* we set a timer to poll at 50ms intervals.
	*/
	static ide_startstop_t do_reset1(ide_drive_t *drive, int do_not_try_atapi)
	{
	ide_hwif_t *hwif = drive->hwif;
	struct ide_io_ports *io_ports = &hwif->io_ports;
	const struct ide_tp_ops *tp_ops = hwif->tp_ops;
	const struct ide_port_ops *port_ops;
	ide_drive_t *tdrive;
	unsigned long flags, timeout;
	int i;
	DEFINE_WAIT(wait);

	spin_lock_irqsave(&hwif->lock, flags);

	/* We must not reset with running handlers */
	BUG_ON(hwif->handler != NULL);

	/* For an ATAPI device, first try an ATAPI SRST. */
	if (drive->media != ide_disk && !do_not_try_atapi) {
	pre_reset(drive);
	tp_ops->dev_select(drive);
	udelay(20);
	tp_ops->exec_command(hwif, ATA_CMD_DEV_RESET);
	ndelay(400);
	hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
	hwif->polling = 1;
	__ide_set_handler(drive, &atapi_reset_pollfunc, HZ/20);
	spin_unlock_irqrestore(&hwif->lock, flags);
	return ide_started;
	}

	/* We must not disturb devices in the IDE_DFLAG_PARKED state. */
	do {
	unsigned long now;

	prepare_to_wait(&ide_park_wq, &wait, TASK_UNINTERRUPTIBLE);
	timeout = jiffies;
	ide_port_for_each_present_dev(i, tdrive, hwif) {
	if ((tdrive->dev_flags & IDE_DFLAG_PARKED) &&
	time_after(tdrive->sleep, timeout))
	timeout = tdrive->sleep;
	}

	now = jiffies;
	if (time_before_eq(timeout, now))
	break;

	spin_unlock_irqrestore(&hwif->lock, flags);
	timeout = schedule_timeout_uninterruptible(timeout - now);
	spin_lock_irqsave(&hwif->lock, flags);
	} while (timeout);
	finish_wait(&ide_park_wq, &wait);

	/*
	* First, reset any device state data we were maintaining
	* for any of the drives on this interface.
	*/
	ide_port_for_each_dev(i, tdrive, hwif)
	pre_reset(tdrive);

	if (io_ports->ctl_addr == 0) {
	spin_unlock_irqrestore(&hwif->lock, flags);
	ide_complete_drive_reset(drive, BLK_STS_IOERR);
	return ide_stopped;
	}

	/*
	* Note that we also set nIEN while resetting the device,
	* to mask unwanted interrupts from the interface during the reset.
	* However, due to the design of PC hardware, this will cause an
	* immediate interrupt due to the edge transition it produces.
	* This single interrupt gives us a "fast poll" for drives that
	* recover from reset very quickly, saving us the first 50ms wait time.
	*/
	/* set SRST and nIEN */
	tp_ops->write_devctl(hwif, ATA_SRST \| ATA_NIEN \| ATA_DEVCTL_OBS);
	/* more than enough time */
	udelay(10);
	/* clear SRST, leave nIEN (unless device is on the quirk list) */
	tp_ops->write_devctl(hwif,
	((drive->dev_flags & IDE_DFLAG_NIEN_QUIRK) ? 0 : ATA_NIEN) \|
	ATA_DEVCTL_OBS);
	/* more than enough time */
	udelay(10);
	hwif->poll_timeout = jiffies + WAIT_WORSTCASE;
	hwif->polling = 1;
	__ide_set_handler(drive, &reset_pollfunc, HZ/20);

	/*
	* Some weird controller like resetting themselves to a strange
	* state when the disks are reset this way. At least, the Winbond
	* 553 documentation says that
	*/
	port_ops = hwif->port_ops;
	if (port_ops && port_ops->resetproc)
	port_ops->resetproc(drive);

	spin_unlock_irqrestore(&hwif->lock, flags);
	return ide_started;
	}

	/*
	* ide_do_reset() is the entry point to the drive/interface reset code.
	*/

	ide_startstop_t ide_do_reset(ide_drive_t *drive)
	{
	return do_reset1(drive, 0);
	}
	EXPORT_SYMBOL(ide_do_reset);