libata-eh.c 56.4 KB
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/*
 *  libata-eh.c - libata error handling
 *
 *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
 *    		    Please ALWAYS copy linux-ide@vger.kernel.org
 *		    on emails.
 *
 *  Copyright 2006 Tejun Heo <htejun@gmail.com>
 *
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as
 *  published by the Free Software Foundation; either version 2, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 *  USA.
 *
 *
 *  libata documentation is available via 'make {ps|pdf}docs',
 *  as Documentation/DocBook/libata.*
 *
 *  Hardware documentation available from http://www.t13.org/ and
 *  http://www.sata-io.org/
 *
 */

#include <linux/kernel.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
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#include "../scsi/scsi_transport_api.h"
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#include <linux/libata.h>

#include "libata.h"

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enum {
	ATA_EH_SPDN_NCQ_OFF		= (1 << 0),
	ATA_EH_SPDN_SPEED_DOWN		= (1 << 1),
	ATA_EH_SPDN_FALLBACK_TO_PIO	= (1 << 2),
};

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/* Waiting in ->prereset can never be reliable.  It's sometimes nice
 * to wait there but it can't be depended upon; otherwise, we wouldn't
 * be resetting.  Just give it enough time for most drives to spin up.
 */
enum {
	ATA_EH_PRERESET_TIMEOUT		= 10 * HZ,
};

/* The following table determines how we sequence resets.  Each entry
 * represents timeout for that try.  The first try can be soft or
 * hardreset.  All others are hardreset if available.  In most cases
 * the first reset w/ 10sec timeout should succeed.  Following entries
 * are mostly for error handling, hotplug and retarded devices.
 */
static const unsigned long ata_eh_reset_timeouts[] = {
	10 * HZ,	/* most drives spin up by 10sec */
	10 * HZ,	/* > 99% working drives spin up before 20sec */
	35 * HZ,	/* give > 30 secs of idleness for retarded devices */
	5 * HZ,		/* and sweet one last chance */
	/* > 1 min has elapsed, give up */
};

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static void __ata_port_freeze(struct ata_port *ap);
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static void ata_eh_finish(struct ata_port *ap);
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#ifdef CONFIG_PM
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static void ata_eh_handle_port_suspend(struct ata_port *ap);
static void ata_eh_handle_port_resume(struct ata_port *ap);
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#else /* CONFIG_PM */
static void ata_eh_handle_port_suspend(struct ata_port *ap)
{ }

static void ata_eh_handle_port_resume(struct ata_port *ap)
{ }
#endif /* CONFIG_PM */
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static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
				 va_list args)
{
	ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
				     ATA_EH_DESC_LEN - ehi->desc_len,
				     fmt, args);
}

/**
 *	__ata_ehi_push_desc - push error description without adding separator
 *	@ehi: target EHI
 *	@fmt: printf format string
 *
 *	Format string according to @fmt and append it to @ehi->desc.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	__ata_ehi_pushv_desc(ehi, fmt, args);
	va_end(args);
}

/**
 *	ata_ehi_push_desc - push error description with separator
 *	@ehi: target EHI
 *	@fmt: printf format string
 *
 *	Format string according to @fmt and append it to @ehi->desc.
 *	If @ehi->desc is not empty, ", " is added in-between.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
	va_list args;

	if (ehi->desc_len)
		__ata_ehi_push_desc(ehi, ", ");

	va_start(args, fmt);
	__ata_ehi_pushv_desc(ehi, fmt, args);
	va_end(args);
}

/**
 *	ata_ehi_clear_desc - clean error description
 *	@ehi: target EHI
 *
 *	Clear @ehi->desc.
 *
 *	LOCKING:
 *	spin_lock_irqsave(host lock)
 */
void ata_ehi_clear_desc(struct ata_eh_info *ehi)
{
	ehi->desc[0] = '\0';
	ehi->desc_len = 0;
}

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static void ata_ering_record(struct ata_ering *ering, int is_io,
			     unsigned int err_mask)
{
	struct ata_ering_entry *ent;

	WARN_ON(!err_mask);

	ering->cursor++;
	ering->cursor %= ATA_ERING_SIZE;

	ent = &ering->ring[ering->cursor];
	ent->is_io = is_io;
	ent->err_mask = err_mask;
	ent->timestamp = get_jiffies_64();
}

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static void ata_ering_clear(struct ata_ering *ering)
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{
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	memset(ering, 0, sizeof(*ering));
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}

static int ata_ering_map(struct ata_ering *ering,
			 int (*map_fn)(struct ata_ering_entry *, void *),
			 void *arg)
{
	int idx, rc = 0;
	struct ata_ering_entry *ent;

	idx = ering->cursor;
	do {
		ent = &ering->ring[idx];
		if (!ent->err_mask)
			break;
		rc = map_fn(ent, arg);
		if (rc)
			break;
		idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
	} while (idx != ering->cursor);

	return rc;
}

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static unsigned int ata_eh_dev_action(struct ata_device *dev)
{
	struct ata_eh_context *ehc = &dev->ap->eh_context;

	return ehc->i.action | ehc->i.dev_action[dev->devno];
}

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static void ata_eh_clear_action(struct ata_device *dev,
				struct ata_eh_info *ehi, unsigned int action)
{
	int i;

	if (!dev) {
		ehi->action &= ~action;
		for (i = 0; i < ATA_MAX_DEVICES; i++)
			ehi->dev_action[i] &= ~action;
	} else {
		/* doesn't make sense for port-wide EH actions */
		WARN_ON(!(action & ATA_EH_PERDEV_MASK));

		/* break ehi->action into ehi->dev_action */
		if (ehi->action & action) {
			for (i = 0; i < ATA_MAX_DEVICES; i++)
				ehi->dev_action[i] |= ehi->action & action;
			ehi->action &= ~action;
		}

		/* turn off the specified per-dev action */
		ehi->dev_action[dev->devno] &= ~action;
	}
}

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/**
 *	ata_scsi_timed_out - SCSI layer time out callback
 *	@cmd: timed out SCSI command
 *
 *	Handles SCSI layer timeout.  We race with normal completion of
 *	the qc for @cmd.  If the qc is already gone, we lose and let
 *	the scsi command finish (EH_HANDLED).  Otherwise, the qc has
 *	timed out and EH should be invoked.  Prevent ata_qc_complete()
 *	from finishing it by setting EH_SCHEDULED and return
 *	EH_NOT_HANDLED.
 *
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 *	TODO: kill this function once old EH is gone.
 *
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 *	LOCKING:
 *	Called from timer context
 *
 *	RETURNS:
 *	EH_HANDLED or EH_NOT_HANDLED
 */
enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
{
	struct Scsi_Host *host = cmd->device->host;
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	struct ata_port *ap = ata_shost_to_port(host);
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	unsigned long flags;
	struct ata_queued_cmd *qc;
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	enum scsi_eh_timer_return ret;
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	DPRINTK("ENTER\n");

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	if (ap->ops->error_handler) {
		ret = EH_NOT_HANDLED;
		goto out;
	}

	ret = EH_HANDLED;
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	spin_lock_irqsave(ap->lock, flags);
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	qc = ata_qc_from_tag(ap, ap->active_tag);
	if (qc) {
		WARN_ON(qc->scsicmd != cmd);
		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
		qc->err_mask |= AC_ERR_TIMEOUT;
		ret = EH_NOT_HANDLED;
	}
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	spin_unlock_irqrestore(ap->lock, flags);
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 out:
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	DPRINTK("EXIT, ret=%d\n", ret);
	return ret;
}

/**
 *	ata_scsi_error - SCSI layer error handler callback
 *	@host: SCSI host on which error occurred
 *
 *	Handles SCSI-layer-thrown error events.
 *
 *	LOCKING:
 *	Inherited from SCSI layer (none, can sleep)
 *
 *	RETURNS:
 *	Zero.
 */
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void ata_scsi_error(struct Scsi_Host *host)
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{
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	struct ata_port *ap = ata_shost_to_port(host);
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	int i, repeat_cnt = ATA_EH_MAX_REPEAT;
	unsigned long flags;
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	DPRINTK("ENTER\n");

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	/* synchronize with port task */
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	ata_port_flush_task(ap);

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	/* synchronize with host lock and sort out timeouts */
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	/* For new EH, all qcs are finished in one of three ways -
	 * normal completion, error completion, and SCSI timeout.
	 * Both cmpletions can race against SCSI timeout.  When normal
	 * completion wins, the qc never reaches EH.  When error
	 * completion wins, the qc has ATA_QCFLAG_FAILED set.
	 *
	 * When SCSI timeout wins, things are a bit more complex.
	 * Normal or error completion can occur after the timeout but
	 * before this point.  In such cases, both types of
	 * completions are honored.  A scmd is determined to have
	 * timed out iff its associated qc is active and not failed.
	 */
	if (ap->ops->error_handler) {
		struct scsi_cmnd *scmd, *tmp;
		int nr_timedout = 0;

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		spin_lock_irqsave(ap->lock, flags);
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		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
			struct ata_queued_cmd *qc;

			for (i = 0; i < ATA_MAX_QUEUE; i++) {
				qc = __ata_qc_from_tag(ap, i);
				if (qc->flags & ATA_QCFLAG_ACTIVE &&
				    qc->scsicmd == scmd)
					break;
			}

			if (i < ATA_MAX_QUEUE) {
				/* the scmd has an associated qc */
				if (!(qc->flags & ATA_QCFLAG_FAILED)) {
					/* which hasn't failed yet, timeout */
					qc->err_mask |= AC_ERR_TIMEOUT;
					qc->flags |= ATA_QCFLAG_FAILED;
					nr_timedout++;
				}
			} else {
				/* Normal completion occurred after
				 * SCSI timeout but before this point.
				 * Successfully complete it.
				 */
				scmd->retries = scmd->allowed;
				scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
			}
		}

		/* If we have timed out qcs.  They belong to EH from
		 * this point but the state of the controller is
		 * unknown.  Freeze the port to make sure the IRQ
		 * handler doesn't diddle with those qcs.  This must
		 * be done atomically w.r.t. setting QCFLAG_FAILED.
		 */
		if (nr_timedout)
			__ata_port_freeze(ap);

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		spin_unlock_irqrestore(ap->lock, flags);
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	} else
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		spin_unlock_wait(ap->lock);
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 repeat:
	/* invoke error handler */
	if (ap->ops->error_handler) {
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		/* process port resume request */
		ata_eh_handle_port_resume(ap);

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		/* fetch & clear EH info */
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		spin_lock_irqsave(ap->lock, flags);
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		memset(&ap->eh_context, 0, sizeof(ap->eh_context));
		ap->eh_context.i = ap->eh_info;
		memset(&ap->eh_info, 0, sizeof(ap->eh_info));

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		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
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		spin_unlock_irqrestore(ap->lock, flags);
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		/* invoke EH, skip if unloading or suspended */
		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
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			ap->ops->error_handler(ap);
		else
			ata_eh_finish(ap);
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		/* process port suspend request */
		ata_eh_handle_port_suspend(ap);

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		/* Exception might have happend after ->error_handler
		 * recovered the port but before this point.  Repeat
		 * EH in such case.
		 */
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		spin_lock_irqsave(ap->lock, flags);
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		if (ap->pflags & ATA_PFLAG_EH_PENDING) {
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			if (--repeat_cnt) {
				ata_port_printk(ap, KERN_INFO,
					"EH pending after completion, "
					"repeating EH (cnt=%d)\n", repeat_cnt);
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				spin_unlock_irqrestore(ap->lock, flags);
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				goto repeat;
			}
			ata_port_printk(ap, KERN_ERR, "EH pending after %d "
					"tries, giving up\n", ATA_EH_MAX_REPEAT);
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			ap->pflags &= ~ATA_PFLAG_EH_PENDING;
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		}

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		/* this run is complete, make sure EH info is clear */
		memset(&ap->eh_info, 0, sizeof(ap->eh_info));

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		/* Clear host_eh_scheduled while holding ap->lock such
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		 * that if exception occurs after this point but
		 * before EH completion, SCSI midlayer will
		 * re-initiate EH.
		 */
		host->host_eh_scheduled = 0;

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		spin_unlock_irqrestore(ap->lock, flags);
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	} else {
		WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL);
		ap->ops->eng_timeout(ap);
	}
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	/* finish or retry handled scmd's and clean up */
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	WARN_ON(host->host_failed || !list_empty(&host->eh_cmd_q));

	scsi_eh_flush_done_q(&ap->eh_done_q);

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	/* clean up */
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	spin_lock_irqsave(ap->lock, flags);
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	if (ap->pflags & ATA_PFLAG_LOADING)
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		ap->pflags &= ~ATA_PFLAG_LOADING;
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	else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
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		queue_delayed_work(ata_aux_wq, &ap->hotplug_task, 0);
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	if (ap->pflags & ATA_PFLAG_RECOVERED)
		ata_port_printk(ap, KERN_INFO, "EH complete\n");
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	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
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	/* tell wait_eh that we're done */
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	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
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	wake_up_all(&ap->eh_wait_q);

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	spin_unlock_irqrestore(ap->lock, flags);
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	DPRINTK("EXIT\n");
}

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/**
 *	ata_port_wait_eh - Wait for the currently pending EH to complete
 *	@ap: Port to wait EH for
 *
 *	Wait until the currently pending EH is complete.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
void ata_port_wait_eh(struct ata_port *ap)
{
	unsigned long flags;
	DEFINE_WAIT(wait);

 retry:
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	spin_lock_irqsave(ap->lock, flags);
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	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
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		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
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		spin_unlock_irqrestore(ap->lock, flags);
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		schedule();
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		spin_lock_irqsave(ap->lock, flags);
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	}
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	finish_wait(&ap->eh_wait_q, &wait);
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	spin_unlock_irqrestore(ap->lock, flags);
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	/* make sure SCSI EH is complete */
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	if (scsi_host_in_recovery(ap->scsi_host)) {
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		msleep(10);
		goto retry;
	}
}

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/**
 *	ata_qc_timeout - Handle timeout of queued command
 *	@qc: Command that timed out
 *
 *	Some part of the kernel (currently, only the SCSI layer)
 *	has noticed that the active command on port @ap has not
 *	completed after a specified length of time.  Handle this
 *	condition by disabling DMA (if necessary) and completing
 *	transactions, with error if necessary.
 *
 *	This also handles the case of the "lost interrupt", where
 *	for some reason (possibly hardware bug, possibly driver bug)
 *	an interrupt was not delivered to the driver, even though the
 *	transaction completed successfully.
 *
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 *	TODO: kill this function once old EH is gone.
 *
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 *	LOCKING:
 *	Inherited from SCSI layer (none, can sleep)
 */
static void ata_qc_timeout(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	u8 host_stat = 0, drv_stat;
	unsigned long flags;

	DPRINTK("ENTER\n");

	ap->hsm_task_state = HSM_ST_IDLE;

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	spin_lock_irqsave(ap->lock, flags);
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	switch (qc->tf.protocol) {

	case ATA_PROT_DMA:
	case ATA_PROT_ATAPI_DMA:
		host_stat = ap->ops->bmdma_status(ap);

		/* before we do anything else, clear DMA-Start bit */
		ap->ops->bmdma_stop(qc);

		/* fall through */

	default:
		ata_altstatus(ap);
		drv_stat = ata_chk_status(ap);

		/* ack bmdma irq events */
		ap->ops->irq_clear(ap);

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		ata_dev_printk(qc->dev, KERN_ERR, "command 0x%x timeout, "
			       "stat 0x%x host_stat 0x%x\n",
			       qc->tf.command, drv_stat, host_stat);
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		/* complete taskfile transaction */
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		qc->err_mask |= AC_ERR_TIMEOUT;
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		break;
	}

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	spin_unlock_irqrestore(ap->lock, flags);
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	ata_eh_qc_complete(qc);

	DPRINTK("EXIT\n");
}

/**
 *	ata_eng_timeout - Handle timeout of queued command
 *	@ap: Port on which timed-out command is active
 *
 *	Some part of the kernel (currently, only the SCSI layer)
 *	has noticed that the active command on port @ap has not
 *	completed after a specified length of time.  Handle this
 *	condition by disabling DMA (if necessary) and completing
 *	transactions, with error if necessary.
 *
 *	This also handles the case of the "lost interrupt", where
 *	for some reason (possibly hardware bug, possibly driver bug)
 *	an interrupt was not delivered to the driver, even though the
 *	transaction completed successfully.
 *
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 *	TODO: kill this function once old EH is gone.
 *
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 *	LOCKING:
 *	Inherited from SCSI layer (none, can sleep)
 */
void ata_eng_timeout(struct ata_port *ap)
{
	DPRINTK("ENTER\n");

	ata_qc_timeout(ata_qc_from_tag(ap, ap->active_tag));

	DPRINTK("EXIT\n");
}

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/**
 *	ata_qc_schedule_eh - schedule qc for error handling
 *	@qc: command to schedule error handling for
 *
 *	Schedule error handling for @qc.  EH will kick in as soon as
 *	other commands are drained.
 *
 *	LOCKING:
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 *	spin_lock_irqsave(host lock)
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 */
void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;

	WARN_ON(!ap->ops->error_handler);

	qc->flags |= ATA_QCFLAG_FAILED;
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	qc->ap->pflags |= ATA_PFLAG_EH_PENDING;
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	/* The following will fail if timeout has already expired.
	 * ata_scsi_error() takes care of such scmds on EH entry.
	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
	 * this function completes.
	 */
	scsi_req_abort_cmd(qc->scsicmd);
}

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/**
 *	ata_port_schedule_eh - schedule error handling without a qc
 *	@ap: ATA port to schedule EH for
 *
 *	Schedule error handling for @ap.  EH will kick in as soon as
 *	all commands are drained.
 *
 *	LOCKING:
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 *	spin_lock_irqsave(host lock)
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 */
void ata_port_schedule_eh(struct ata_port *ap)
{
	WARN_ON(!ap->ops->error_handler);

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	if (ap->pflags & ATA_PFLAG_INITIALIZING)
		return;

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	ap->pflags |= ATA_PFLAG_EH_PENDING;
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	scsi_schedule_eh(ap->scsi_host);
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	DPRINTK("port EH scheduled\n");
}

/**
 *	ata_port_abort - abort all qc's on the port
 *	@ap: ATA port to abort qc's for
 *
 *	Abort all active qc's of @ap and schedule EH.
 *
 *	LOCKING:
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 *	spin_lock_irqsave(host lock)
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 *
 *	RETURNS:
 *	Number of aborted qc's.
 */
int ata_port_abort(struct ata_port *ap)
{
	int tag, nr_aborted = 0;

	WARN_ON(!ap->ops->error_handler);

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);

		if (qc) {
			qc->flags |= ATA_QCFLAG_FAILED;
			ata_qc_complete(qc);
			nr_aborted++;
		}
	}

	if (!nr_aborted)
		ata_port_schedule_eh(ap);

	return nr_aborted;
}

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/**
 *	__ata_port_freeze - freeze port
 *	@ap: ATA port to freeze
 *
 *	This function is called when HSM violation or some other
 *	condition disrupts normal operation of the port.  Frozen port
 *	is not allowed to perform any operation until the port is
 *	thawed, which usually follows a successful reset.
 *
 *	ap->ops->freeze() callback can be used for freezing the port
 *	hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
 *	port cannot be frozen hardware-wise, the interrupt handler
 *	must ack and clear interrupts unconditionally while the port
 *	is frozen.
 *
 *	LOCKING:
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 *	spin_lock_irqsave(host lock)
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 */
static void __ata_port_freeze(struct ata_port *ap)
{
	WARN_ON(!ap->ops->error_handler);

	if (ap->ops->freeze)
		ap->ops->freeze(ap);

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	ap->pflags |= ATA_PFLAG_FROZEN;
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	DPRINTK("ata%u port frozen\n", ap->print_id);
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}

/**
 *	ata_port_freeze - abort & freeze port
 *	@ap: ATA port to freeze
 *
 *	Abort and freeze @ap.
 *
 *	LOCKING:
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 *	spin_lock_irqsave(host lock)
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 *
 *	RETURNS:
 *	Number of aborted commands.
 */
int ata_port_freeze(struct ata_port *ap)
{
	int nr_aborted;

	WARN_ON(!ap->ops->error_handler);

	nr_aborted = ata_port_abort(ap);
	__ata_port_freeze(ap);

	return nr_aborted;
}

/**
 *	ata_eh_freeze_port - EH helper to freeze port
 *	@ap: ATA port to freeze
 *
 *	Freeze @ap.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_freeze_port(struct ata_port *ap)
{
	unsigned long flags;

	if (!ap->ops->error_handler)
		return;

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	spin_lock_irqsave(ap->lock, flags);
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	__ata_port_freeze(ap);
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	spin_unlock_irqrestore(ap->lock, flags);
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}

/**
 *	ata_port_thaw_port - EH helper to thaw port
 *	@ap: ATA port to thaw
 *
 *	Thaw frozen port @ap.
 *
 *	LOCKING:
 *	None.
 */
void ata_eh_thaw_port(struct ata_port *ap)
{
	unsigned long flags;

	if (!ap->ops->error_handler)
		return;

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	spin_lock_irqsave(ap->lock, flags);
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	ap->pflags &= ~ATA_PFLAG_FROZEN;
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	if (ap->ops->thaw)
		ap->ops->thaw(ap);

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	spin_unlock_irqrestore(ap->lock, flags);
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	DPRINTK("ata%u port thawed\n", ap->print_id);
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}

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static void ata_eh_scsidone(struct scsi_cmnd *scmd)
{
	/* nada */
}

static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
{
	struct ata_port *ap = qc->ap;
	struct scsi_cmnd *scmd = qc->scsicmd;
	unsigned long flags;

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	spin_lock_irqsave(ap->lock, flags);
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	qc->scsidone = ata_eh_scsidone;
	__ata_qc_complete(qc);
	WARN_ON(ata_tag_valid(qc->tag));
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	spin_unlock_irqrestore(ap->lock, flags);
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	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
}

/**
 *	ata_eh_qc_complete - Complete an active ATA command from EH
 *	@qc: Command to complete
 *
 *	Indicate to the mid and upper layers that an ATA command has
 *	completed.  To be used from EH.
 */
void ata_eh_qc_complete(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	scmd->retries = scmd->allowed;
	__ata_eh_qc_complete(qc);
}

/**
 *	ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
 *	@qc: Command to retry
 *
 *	Indicate to the mid and upper layers that an ATA command
 *	should be retried.  To be used from EH.
 *
 *	SCSI midlayer limits the number of retries to scmd->allowed.
 *	scmd->retries is decremented for commands which get retried
 *	due to unrelated failures (qc->err_mask is zero).
 */
void ata_eh_qc_retry(struct ata_queued_cmd *qc)
{
	struct scsi_cmnd *scmd = qc->scsicmd;
	if (!qc->err_mask && scmd->retries)
		scmd->retries--;
	__ata_eh_qc_complete(qc);
}
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/**
 *	ata_eh_detach_dev - detach ATA device
 *	@dev: ATA device to detach
 *
 *	Detach @dev.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_detach_dev(struct ata_device *dev)
{
	struct ata_port *ap = dev->ap;
	unsigned long flags;

	ata_dev_disable(dev);

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	spin_lock_irqsave(ap->lock, flags);
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	dev->flags &= ~ATA_DFLAG_DETACH;

	if (ata_scsi_offline_dev(dev)) {
		dev->flags |= ATA_DFLAG_DETACHED;
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		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
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	}

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	/* clear per-dev EH actions */
	ata_eh_clear_action(dev, &ap->eh_info, ATA_EH_PERDEV_MASK);
	ata_eh_clear_action(dev, &ap->eh_context.i, ATA_EH_PERDEV_MASK);

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	spin_unlock_irqrestore(ap->lock, flags);
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}

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/**
 *	ata_eh_about_to_do - about to perform eh_action
 *	@ap: target ATA port
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 *	@dev: target ATA dev for per-dev action (can be NULL)
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 *	@action: action about to be performed
 *
 *	Called just before performing EH actions to clear related bits
 *	in @ap->eh_info such that eh actions are not unnecessarily
 *	repeated.
 *
 *	LOCKING:
 *	None.
 */
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static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
			       unsigned int action)
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{
	unsigned long flags;
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	struct ata_eh_info *ehi = &ap->eh_info;
	struct ata_eh_context *ehc = &ap->eh_context;
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	spin_lock_irqsave(ap->lock, flags);
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	/* Reset is represented by combination of actions and EHI
	 * flags.  Suck in all related bits before clearing eh_info to
	 * avoid losing requested action.
	 */
	if (action & ATA_EH_RESET_MASK) {
		ehc->i.action |= ehi->action & ATA_EH_RESET_MASK;
		ehc->i.flags |= ehi->flags & ATA_EHI_RESET_MODIFIER_MASK;

		/* make sure all reset actions are cleared & clear EHI flags */
		action |= ATA_EH_RESET_MASK;
		ehi->flags &= ~ATA_EHI_RESET_MODIFIER_MASK;
	}

	ata_eh_clear_action(dev, ehi, action);
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	if (!(ehc->i.flags & ATA_EHI_QUIET))
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		ap->pflags |= ATA_PFLAG_RECOVERED;

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	spin_unlock_irqrestore(ap->lock, flags);
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}

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/**
 *	ata_eh_done - EH action complete
 *	@ap: target ATA port
 *	@dev: target ATA dev for per-dev action (can be NULL)
 *	@action: action just completed
 *
 *	Called right after performing EH actions to clear related bits
 *	in @ap->eh_context.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_done(struct ata_port *ap, struct ata_device *dev,
			unsigned int action)
{
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	/* if reset is complete, clear all reset actions & reset modifier */
	if (action & ATA_EH_RESET_MASK) {
		action |= ATA_EH_RESET_MASK;
		ap->eh_context.i.flags &= ~ATA_EHI_RESET_MODIFIER_MASK;
	}

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	ata_eh_clear_action(dev, &ap->eh_context.i, action);
}

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/**
 *	ata_err_string - convert err_mask to descriptive string
 *	@err_mask: error mask to convert to string
 *
 *	Convert @err_mask to descriptive string.  Errors are
 *	prioritized according to severity and only the most severe
 *	error is reported.
 *
 *	LOCKING:
 *	None.
 *
 *	RETURNS:
 *	Descriptive string for @err_mask
 */
static const char * ata_err_string(unsigned int err_mask)
{
	if (err_mask & AC_ERR_HOST_BUS)
		return "host bus error";
	if (err_mask & AC_ERR_ATA_BUS)
		return "ATA bus error";
	if (err_mask & AC_ERR_TIMEOUT)
		return "timeout";
	if (err_mask & AC_ERR_HSM)
		return "HSM violation";
	if (err_mask & AC_ERR_SYSTEM)
		return "internal error";
	if (err_mask & AC_ERR_MEDIA)
		return "media error";
	if (err_mask & AC_ERR_INVALID)
		return "invalid argument";
	if (err_mask & AC_ERR_DEV)
		return "device error";
	return "unknown error";
}

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/**
 *	ata_read_log_page - read a specific log page
 *	@dev: target device
 *	@page: page to read
 *	@buf: buffer to store read page
 *	@sectors: number of sectors to read
 *
 *	Read log page using READ_LOG_EXT command.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, AC_ERR_* mask otherwise.
 */
static unsigned int ata_read_log_page(struct ata_device *dev,
				      u8 page, void *buf, unsigned int sectors)
{
	struct ata_taskfile tf;
	unsigned int err_mask;

	DPRINTK("read log page - page %d\n", page);

	ata_tf_init(dev, &tf);
	tf.command = ATA_CMD_READ_LOG_EXT;
	tf.lbal = page;
	tf.nsect = sectors;
	tf.hob_nsect = sectors >> 8;
	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;
	tf.protocol = ATA_PROT_PIO;

	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
				     buf, sectors * ATA_SECT_SIZE);

	DPRINTK("EXIT, err_mask=%x\n", err_mask);
	return err_mask;
}

/**
 *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
 *	@dev: Device to read log page 10h from
 *	@tag: Resulting tag of the failed command
 *	@tf: Resulting taskfile registers of the failed command
 *
 *	Read log page 10h to obtain NCQ error details and clear error
 *	condition.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno otherwise.
 */
static int ata_eh_read_log_10h(struct ata_device *dev,
			       int *tag, struct ata_taskfile *tf)
{
	u8 *buf = dev->ap->sector_buf;
	unsigned int err_mask;
	u8 csum;
	int i;

	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, buf, 1);
	if (err_mask)
		return -EIO;

	csum = 0;
	for (i = 0; i < ATA_SECT_SIZE; i++)
		csum += buf[i];
	if (csum)
		ata_dev_printk(dev, KERN_WARNING,
			       "invalid checksum 0x%x on log page 10h\n", csum);

	if (buf[0] & 0x80)
		return -ENOENT;

	*tag = buf[0] & 0x1f;

	tf->command = buf[2];
	tf->feature = buf[3];
	tf->lbal = buf[4];
	tf->lbam = buf[5];
	tf->lbah = buf[6];
	tf->device = buf[7];
	tf->hob_lbal = buf[8];
	tf->hob_lbam = buf[9];
	tf->hob_lbah = buf[10];
	tf->nsect = buf[12];
	tf->hob_nsect = buf[13];

	return 0;
}

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/**
 *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
 *	@dev: device to perform REQUEST_SENSE to
 *	@sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
 *
 *	Perform ATAPI REQUEST_SENSE after the device reported CHECK
 *	SENSE.  This function is EH helper.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, AC_ERR_* mask on failure
 */
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static unsigned int atapi_eh_request_sense(struct ata_queued_cmd *qc)
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{
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	struct ata_device *dev = qc->dev;
	unsigned char *sense_buf = qc->scsicmd->sense_buffer;
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	struct ata_port *ap = dev->ap;
	struct ata_taskfile tf;
	u8 cdb[ATAPI_CDB_LEN];

	DPRINTK("ATAPI request sense\n");

	/* FIXME: is this needed? */
	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);

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	/* initialize sense_buf with the error register,
	 * for the case where they are -not- overwritten
	 */
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	sense_buf[0] = 0x70;
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	sense_buf[2] = qc->result_tf.feature >> 4;

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	/* some devices time out if garbage left in tf */
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	ata_tf_init(dev, &tf);
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	memset(cdb, 0, ATAPI_CDB_LEN);
	cdb[0] = REQUEST_SENSE;
	cdb[4] = SCSI_SENSE_BUFFERSIZE;

	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
	tf.command = ATA_CMD_PACKET;

	/* is it pointless to prefer PIO for "safety reasons"? */
	if (ap->flags & ATA_FLAG_PIO_DMA) {
		tf.protocol = ATA_PROT_ATAPI_DMA;
		tf.feature |= ATAPI_PKT_DMA;
	} else {
		tf.protocol = ATA_PROT_ATAPI;
		tf.lbam = (8 * 1024) & 0xff;
		tf.lbah = (8 * 1024) >> 8;
	}

	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
				 sense_buf, SCSI_SENSE_BUFFERSIZE);
}

/**
 *	ata_eh_analyze_serror - analyze SError for a failed port
 *	@ap: ATA port to analyze SError for
 *
 *	Analyze SError if available and further determine cause of
 *	failure.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_analyze_serror(struct ata_port *ap)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	u32 serror = ehc->i.serror;
	unsigned int err_mask = 0, action = 0;

	if (serror & SERR_PERSISTENT) {
		err_mask |= AC_ERR_ATA_BUS;
		action |= ATA_EH_HARDRESET;
	}
	if (serror &
	    (SERR_DATA_RECOVERED | SERR_COMM_RECOVERED | SERR_DATA)) {
		err_mask |= AC_ERR_ATA_BUS;
		action |= ATA_EH_SOFTRESET;
	}
	if (serror & SERR_PROTOCOL) {
		err_mask |= AC_ERR_HSM;
		action |= ATA_EH_SOFTRESET;
	}
	if (serror & SERR_INTERNAL) {
		err_mask |= AC_ERR_SYSTEM;
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		action |= ATA_EH_HARDRESET;
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	}
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	if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG))
		ata_ehi_hotplugged(&ehc->i);
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	ehc->i.err_mask |= err_mask;
	ehc->i.action |= action;
}

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/**
 *	ata_eh_analyze_ncq_error - analyze NCQ error
 *	@ap: ATA port to analyze NCQ error for
 *
 *	Read log page 10h, determine the offending qc and acquire
 *	error status TF.  For NCQ device errors, all LLDDs have to do
 *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
 *	care of the rest.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_analyze_ncq_error(struct ata_port *ap)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	struct ata_device *dev = ap->device;
	struct ata_queued_cmd *qc;
	struct ata_taskfile tf;
	int tag, rc;

	/* if frozen, we can't do much */
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	if (ap->pflags & ATA_PFLAG_FROZEN)
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		return;

	/* is it NCQ device error? */
	if (!ap->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
		return;

	/* has LLDD analyzed already? */
	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		if (qc->err_mask)
			return;
	}

	/* okay, this error is ours */
	rc = ata_eh_read_log_10h(dev, &tag, &tf);
	if (rc) {
		ata_port_printk(ap, KERN_ERR, "failed to read log page 10h "
				"(errno=%d)\n", rc);
		return;
	}

	if (!(ap->sactive & (1 << tag))) {
		ata_port_printk(ap, KERN_ERR, "log page 10h reported "
				"inactive tag %d\n", tag);
		return;
	}

	/* we've got the perpetrator, condemn it */
	qc = __ata_qc_from_tag(ap, tag);
	memcpy(&qc->result_tf, &tf, sizeof(tf));
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	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
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	ehc->i.err_mask &= ~AC_ERR_DEV;
}

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/**
 *	ata_eh_analyze_tf - analyze taskfile of a failed qc
 *	@qc: qc to analyze
 *	@tf: Taskfile registers to analyze
 *
 *	Analyze taskfile of @qc and further determine cause of
 *	failure.  This function also requests ATAPI sense data if
 *	avaliable.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	Determined recovery action
 */
static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
				      const struct ata_taskfile *tf)
{
	unsigned int tmp, action = 0;
	u8 stat = tf->command, err = tf->feature;

	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
		qc->err_mask |= AC_ERR_HSM;
		return ATA_EH_SOFTRESET;
	}

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	if (stat & (ATA_ERR | ATA_DF))
		qc->err_mask |= AC_ERR_DEV;
	else
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		return 0;

	switch (qc->dev->class) {
	case ATA_DEV_ATA:
		if (err & ATA_ICRC)
			qc->err_mask |= AC_ERR_ATA_BUS;
		if (err & ATA_UNC)
			qc->err_mask |= AC_ERR_MEDIA;
		if (err & ATA_IDNF)
			qc->err_mask |= AC_ERR_INVALID;
		break;

	case ATA_DEV_ATAPI:
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		if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
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			tmp = atapi_eh_request_sense(qc);
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			if (!tmp) {
				/* ATA_QCFLAG_SENSE_VALID is used to
				 * tell atapi_qc_complete() that sense
				 * data is already valid.
				 *
				 * TODO: interpret sense data and set
				 * appropriate err_mask.
				 */
				qc->flags |= ATA_QCFLAG_SENSE_VALID;
			} else
				qc->err_mask |= tmp;
		}
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	}

	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
		action |= ATA_EH_SOFTRESET;

	return action;
}

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static int ata_eh_categorize_error(int is_io, unsigned int err_mask)
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{
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	if (err_mask & AC_ERR_ATA_BUS)
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		return 1;

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	if (err_mask & AC_ERR_TIMEOUT)
		return 2;

	if (is_io) {
		if (err_mask & AC_ERR_HSM)
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			return 2;
1277 1278 1279
		if ((err_mask &
		     (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
			return 3;
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1280 1281 1282 1283 1284
	}

	return 0;
}

1285
struct speed_down_verdict_arg {
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1286
	u64 since;
1287
	int nr_errors[4];
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1288 1289
};

1290
static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
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{
1292 1293
	struct speed_down_verdict_arg *arg = void_arg;
	int cat = ata_eh_categorize_error(ent->is_io, ent->err_mask);
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1294 1295 1296 1297

	if (ent->timestamp < arg->since)
		return -1;

1298
	arg->nr_errors[cat]++;
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1299 1300 1301 1302
	return 0;
}

/**
1303
 *	ata_eh_speed_down_verdict - Determine speed down verdict
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1304 1305 1306
 *	@dev: Device of interest
 *
 *	This function examines error ring of @dev and determines
1307 1308
 *	whether NCQ needs to be turned off, transfer speed should be
 *	stepped down, or falling back to PIO is necessary.
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 *
1310
 *	Cat-1 is ATA_BUS error for any command.
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 *
1312 1313 1314 1315
 *	Cat-2 is TIMEOUT for any command or HSM violation for known
 *	supported commands.
 *
 *	Cat-3 is is unclassified DEV error for known supported
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 *	command.
 *
1318 1319 1320 1321 1322 1323 1324 1325 1326
 *	NCQ needs to be turned off if there have been more than 3
 *	Cat-2 + Cat-3 errors during last 10 minutes.
 *
 *	Speed down is necessary if there have been more than 3 Cat-1 +
 *	Cat-2 errors or 10 Cat-3 errors during last 10 minutes.
 *
 *	Falling back to PIO mode is necessary if there have been more
 *	than 10 Cat-1 + Cat-2 + Cat-3 errors during last 5 minutes.
 *
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 *	LOCKING:
 *	Inherited from caller.
 *
 *	RETURNS:
1331
 *	OR of ATA_EH_SPDN_* flags.
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 */
1333
static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
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{
1335 1336 1337 1338
	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
	u64 j64 = get_jiffies_64();
	struct speed_down_verdict_arg arg;
	unsigned int verdict = 0;
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1340 1341 1342 1343
	/* scan past 10 mins of error history */
	memset(&arg, 0, sizeof(arg));
	arg.since = j64 - min(j64, j10mins);
	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
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1345 1346 1347 1348
	if (arg.nr_errors[2] + arg.nr_errors[3] > 3)
		verdict |= ATA_EH_SPDN_NCQ_OFF;
	if (arg.nr_errors[1] + arg.nr_errors[2] > 3 || arg.nr_errors[3] > 10)
		verdict |= ATA_EH_SPDN_SPEED_DOWN;
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1350
	/* scan past 3 mins of error history */
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	memset(&arg, 0, sizeof(arg));
1352 1353
	arg.since = j64 - min(j64, j5mins);
	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
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1355 1356
	if (arg.nr_errors[1] + arg.nr_errors[2] + arg.nr_errors[3] > 10)
		verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;
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1358
	return verdict;
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}

/**
 *	ata_eh_speed_down - record error and speed down if necessary
 *	@dev: Failed device
 *	@is_io: Did the device fail during normal IO?
 *	@err_mask: err_mask of the error
 *
 *	Record error and examine error history to determine whether
 *	adjusting transmission speed is necessary.  It also sets
 *	transmission limits appropriately if such adjustment is
 *	necessary.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
1376
 *	Determined recovery action.
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 */
1378 1379
static unsigned int ata_eh_speed_down(struct ata_device *dev, int is_io,
				      unsigned int err_mask)
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{
1381 1382 1383 1384 1385
	unsigned int verdict;
	unsigned int action = 0;

	/* don't bother if Cat-0 error */
	if (ata_eh_categorize_error(is_io, err_mask) == 0)
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		return 0;

	/* record error and determine whether speed down is necessary */
	ata_ering_record(&dev->ering, is_io, err_mask);
1390
	verdict = ata_eh_speed_down_verdict(dev);
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1392 1393 1394 1395 1396 1397 1398 1399 1400
	/* turn off NCQ? */
	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
		dev->flags |= ATA_DFLAG_NCQ_OFF;
		ata_dev_printk(dev, KERN_WARNING,
			       "NCQ disabled due to excessive errors\n");
		goto done;
	}
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1402 1403 1404 1405 1406 1407 1408
	/* speed down? */
	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
		/* speed down SATA link speed if possible */
		if (sata_down_spd_limit(dev->ap) == 0) {
			action |= ATA_EH_HARDRESET;
			goto done;
		}
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1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443
		/* lower transfer mode */
		if (dev->spdn_cnt < 2) {
			static const int dma_dnxfer_sel[] =
				{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
			static const int pio_dnxfer_sel[] =
				{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
			int sel;

			if (dev->xfer_shift != ATA_SHIFT_PIO)
				sel = dma_dnxfer_sel[dev->spdn_cnt];
			else
				sel = pio_dnxfer_sel[dev->spdn_cnt];

			dev->spdn_cnt++;

			if (ata_down_xfermask_limit(dev, sel) == 0) {
				action |= ATA_EH_SOFTRESET;
				goto done;
			}
		}
	}

	/* Fall back to PIO?  Slowing down to PIO is meaningless for
	 * SATA.  Consider it only for PATA.
	 */
	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
	    (dev->ap->cbl != ATA_CBL_SATA) &&
	    (dev->xfer_shift != ATA_SHIFT_PIO)) {
		if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
			dev->spdn_cnt = 0;
			action |= ATA_EH_SOFTRESET;
			goto done;
		}
	}
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	return 0;
1446 1447 1448 1449
 done:
	/* device has been slowed down, blow error history */
	ata_ering_clear(&dev->ering);
	return action;
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}

/**
 *	ata_eh_autopsy - analyze error and determine recovery action
 *	@ap: ATA port to perform autopsy on
 *
 *	Analyze why @ap failed and determine which recovery action is
 *	needed.  This function also sets more detailed AC_ERR_* values
 *	and fills sense data for ATAPI CHECK SENSE.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_autopsy(struct ata_port *ap)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	unsigned int all_err_mask = 0;
	int tag, is_io = 0;
	u32 serror;
	int rc;

	DPRINTK("ENTER\n");

1473 1474 1475
	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
		return;

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	/* obtain and analyze SError */
	rc = sata_scr_read(ap, SCR_ERROR, &serror);
	if (rc == 0) {
		ehc->i.serror |= serror;
		ata_eh_analyze_serror(ap);
1481 1482 1483
	} else if (rc != -EOPNOTSUPP) {
		/* SError read failed, force hardreset and probing */
		ata_ehi_schedule_probe(&ehc->i);
1484
		ehc->i.action |= ATA_EH_HARDRESET;
1485 1486
		ehc->i.err_mask |= AC_ERR_OTHER;
	}
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1488 1489 1490
	/* analyze NCQ failure */
	ata_eh_analyze_ncq_error(ap);

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	/* any real error trumps AC_ERR_OTHER */
	if (ehc->i.err_mask & ~AC_ERR_OTHER)
		ehc->i.err_mask &= ~AC_ERR_OTHER;

	all_err_mask |= ehc->i.err_mask;

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		/* inherit upper level err_mask */
		qc->err_mask |= ehc->i.err_mask;

		/* analyze TF */
1507
		ehc->i.action |= ata_eh_analyze_tf(qc, &qc->result_tf);
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		/* DEV errors are probably spurious in case of ATA_BUS error */
		if (qc->err_mask & AC_ERR_ATA_BUS)
			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
					  AC_ERR_INVALID);

		/* any real error trumps unknown error */
		if (qc->err_mask & ~AC_ERR_OTHER)
			qc->err_mask &= ~AC_ERR_OTHER;

		/* SENSE_VALID trumps dev/unknown error and revalidation */
		if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
1521
			ehc->i.action &= ~ATA_EH_REVALIDATE;
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		}

		/* accumulate error info */
1525
		ehc->i.dev = qc->dev;
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		all_err_mask |= qc->err_mask;
		if (qc->flags & ATA_QCFLAG_IO)
			is_io = 1;
	}

1531
	/* enforce default EH actions */
1532
	if (ap->pflags & ATA_PFLAG_FROZEN ||
1533
	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
1534
		ehc->i.action |= ATA_EH_SOFTRESET;
1535
	else if (all_err_mask)
1536
		ehc->i.action |= ATA_EH_REVALIDATE;
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1538
	/* if we have offending qcs and the associated failed device */
1539
	if (ehc->i.dev) {
1540
		/* speed down */
1541 1542
		ehc->i.action |= ata_eh_speed_down(ehc->i.dev, is_io,
						   all_err_mask);
1543 1544

		/* perform per-dev EH action only on the offending device */
1545 1546 1547
		ehc->i.dev_action[ehc->i.dev->devno] |=
			ehc->i.action & ATA_EH_PERDEV_MASK;
		ehc->i.action &= ~ATA_EH_PERDEV_MASK;
1548 1549
	}

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1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586
	DPRINTK("EXIT\n");
}

/**
 *	ata_eh_report - report error handling to user
 *	@ap: ATA port EH is going on
 *
 *	Report EH to user.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_report(struct ata_port *ap)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	const char *frozen, *desc;
	int tag, nr_failed = 0;

	desc = NULL;
	if (ehc->i.desc[0] != '\0')
		desc = ehc->i.desc;

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;
		if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
			continue;

		nr_failed++;
	}

	if (!nr_failed && !ehc->i.err_mask)
		return;

	frozen = "";
1587
	if (ap->pflags & ATA_PFLAG_FROZEN)
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1588 1589 1590
		frozen = " frozen";

	if (ehc->i.dev) {
1591 1592 1593 1594
		ata_dev_printk(ehc->i.dev, KERN_ERR, "exception Emask 0x%x "
			       "SAct 0x%x SErr 0x%x action 0x%x%s\n",
			       ehc->i.err_mask, ap->sactive, ehc->i.serror,
			       ehc->i.action, frozen);
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1595
		if (desc)
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1596
			ata_dev_printk(ehc->i.dev, KERN_ERR, "%s\n", desc);
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	} else {
1598 1599 1600 1601
		ata_port_printk(ap, KERN_ERR, "exception Emask 0x%x "
				"SAct 0x%x SErr 0x%x action 0x%x%s\n",
				ehc->i.err_mask, ap->sactive, ehc->i.serror,
				ehc->i.action, frozen);
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1602
		if (desc)
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1603
			ata_port_printk(ap, KERN_ERR, "%s\n", desc);
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1604 1605 1606
	}

	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1607 1608 1609 1610 1611 1612
		static const char *dma_str[] = {
			[DMA_BIDIRECTIONAL]	= "bidi",
			[DMA_TO_DEVICE]		= "out",
			[DMA_FROM_DEVICE]	= "in",
			[DMA_NONE]		= "",
		};
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1613
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
1614
		struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
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1615 1616 1617 1618

		if (!(qc->flags & ATA_QCFLAG_FAILED) || !qc->err_mask)
			continue;

1619 1620
		ata_dev_printk(qc->dev, KERN_ERR,
			"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
1621
			"tag %d cdb 0x%x data %u %s\n         "
1622
			"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
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			"Emask 0x%x (%s)%s\n",
1624 1625 1626 1627
			cmd->command, cmd->feature, cmd->nsect,
			cmd->lbal, cmd->lbam, cmd->lbah,
			cmd->hob_feature, cmd->hob_nsect,
			cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
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1628
			cmd->device, qc->tag, qc->cdb[0], qc->nbytes,
1629
			dma_str[qc->dma_dir],
1630 1631 1632 1633
			res->command, res->feature, res->nsect,
			res->lbal, res->lbam, res->lbah,
			res->hob_feature, res->hob_nsect,
			res->hob_lbal, res->hob_lbam, res->hob_lbah,
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1634 1635
			res->device, qc->err_mask, ata_err_string(qc->err_mask),
			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
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1636 1637 1638
	}
}

1639
static int ata_do_reset(struct ata_port *ap, ata_reset_fn_t reset,
1640
			unsigned int *classes, unsigned long deadline)
1641 1642 1643 1644 1645 1646
{
	int i, rc;

	for (i = 0; i < ATA_MAX_DEVICES; i++)
		classes[i] = ATA_DEV_UNKNOWN;

1647
	rc = reset(ap, classes, deadline);
1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
	if (rc)
		return rc;

	/* If any class isn't ATA_DEV_UNKNOWN, consider classification
	 * is complete and convert all ATA_DEV_UNKNOWN to
	 * ATA_DEV_NONE.
	 */
	for (i = 0; i < ATA_MAX_DEVICES; i++)
		if (classes[i] != ATA_DEV_UNKNOWN)
			break;

	if (i < ATA_MAX_DEVICES)
		for (i = 0; i < ATA_MAX_DEVICES; i++)
			if (classes[i] == ATA_DEV_UNKNOWN)
				classes[i] = ATA_DEV_NONE;

	return 0;
}

1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
static int ata_eh_followup_srst_needed(int rc, int classify,
				       const unsigned int *classes)
{
	if (rc == -EAGAIN)
		return 1;
	if (rc != 0)
		return 0;
	if (classify && classes[0] == ATA_DEV_UNKNOWN)
		return 1;
	return 0;
}

static int ata_eh_reset(struct ata_port *ap, int classify,
1680
			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
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1681 1682 1683
			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
{
	struct ata_eh_context *ehc = &ap->eh_context;
1684
	unsigned int *classes = ehc->classes;
1685
	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
T
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1686 1687
	int try = 0;
	unsigned long deadline;
1688
	unsigned int action;
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1689
	ata_reset_fn_t reset;
1690
	int i, rc;
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1691

1692 1693 1694
	/* about to reset */
	ata_eh_about_to_do(ap, NULL, ehc->i.action & ATA_EH_RESET_MASK);

1695 1696 1697 1698 1699
	/* Determine which reset to use and record in ehc->i.action.
	 * prereset() may examine and modify it.
	 */
	action = ehc->i.action;
	ehc->i.action &= ~ATA_EH_RESET_MASK;
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	if (softreset && (!hardreset || (!sata_set_spd_needed(ap) &&
1701 1702
					 !(action & ATA_EH_HARDRESET))))
		ehc->i.action |= ATA_EH_SOFTRESET;
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	else
1704 1705 1706
		ehc->i.action |= ATA_EH_HARDRESET;

	if (prereset) {
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		rc = prereset(ap, jiffies + ATA_EH_PRERESET_TIMEOUT);
1708
		if (rc) {
1709
			if (rc == -ENOENT) {
1710 1711
				ata_port_printk(ap, KERN_DEBUG,
						"port disabled. ignoring.\n");
1712
				ap->eh_context.i.action &= ~ATA_EH_RESET_MASK;
1713 1714 1715 1716 1717

				for (i = 0; i < ATA_MAX_DEVICES; i++)
					classes[i] = ATA_DEV_NONE;

				rc = 0;
1718 1719
			} else
				ata_port_printk(ap, KERN_ERR,
1720
					"prereset failed (errno=%d)\n", rc);
1721
			goto out;
1722 1723 1724 1725 1726
		}
	}

	/* prereset() might have modified ehc->i.action */
	if (ehc->i.action & ATA_EH_HARDRESET)
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		reset = hardreset;
1728 1729 1730 1731 1732 1733
	else if (ehc->i.action & ATA_EH_SOFTRESET)
		reset = softreset;
	else {
		/* prereset told us not to reset, bang classes and return */
		for (i = 0; i < ATA_MAX_DEVICES; i++)
			classes[i] = ATA_DEV_NONE;
1734 1735
		rc = 0;
		goto out;
1736 1737 1738 1739 1740 1741 1742 1743 1744
	}

	/* did prereset() screw up?  if so, fix up to avoid oopsing */
	if (!reset) {
		if (softreset)
			reset = softreset;
		else
			reset = hardreset;
	}
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1745 1746

 retry:
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1747 1748
	deadline = jiffies + ata_eh_reset_timeouts[try++];

1749 1750 1751 1752
	/* shut up during boot probing */
	if (verbose)
		ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
				reset == softreset ? "soft" : "hard");
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1754
	/* mark that this EH session started with reset */
1755 1756 1757 1758
	if (reset == hardreset)
		ehc->i.flags |= ATA_EHI_DID_HARDRESET;
	else
		ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
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	rc = ata_do_reset(ap, reset, classes, deadline);
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1762 1763 1764 1765 1766 1767 1768 1769 1770
	if (reset == hardreset &&
	    ata_eh_followup_srst_needed(rc, classify, classes)) {
		/* okay, let's do follow-up softreset */
		reset = softreset;

		if (!reset) {
			ata_port_printk(ap, KERN_ERR,
					"follow-up softreset required "
					"but no softreset avaliable\n");
1771 1772
			rc = -EINVAL;
			goto out;
1773 1774
		}

1775
		ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK);
T
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1776
		rc = ata_do_reset(ap, reset, classes, deadline);
1777 1778 1779 1780 1781

		if (rc == 0 && classify &&
		    classes[0] == ATA_DEV_UNKNOWN) {
			ata_port_printk(ap, KERN_ERR,
					"classification failed\n");
1782 1783
			rc = -EINVAL;
			goto out;
1784 1785 1786
		}
	}

T
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1787 1788
	if (rc && try < ARRAY_SIZE(ata_eh_reset_timeouts)) {
		unsigned long now = jiffies;
1789

T
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1790 1791
		if (time_before(now, deadline)) {
			unsigned long delta = deadline - jiffies;
1792

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1793 1794 1795 1796 1797 1798
			ata_port_printk(ap, KERN_WARNING, "reset failed "
				"(errno=%d), retrying in %u secs\n",
				rc, (jiffies_to_msecs(delta) + 999) / 1000);

			schedule_timeout_uninterruptible(delta);
		}
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1800
		if (rc == -EPIPE ||
T
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1801
		    try == ARRAY_SIZE(ata_eh_reset_timeouts) - 1)
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1802 1803 1804 1805 1806 1807 1808
			sata_down_spd_limit(ap);
		if (hardreset)
			reset = hardreset;
		goto retry;
	}

	if (rc == 0) {
1809 1810
		u32 sstatus;

1811 1812 1813 1814 1815 1816
		/* After the reset, the device state is PIO 0 and the
		 * controller state is undefined.  Record the mode.
		 */
		for (i = 0; i < ATA_MAX_DEVICES; i++)
			ap->device[i].pio_mode = XFER_PIO_0;

1817 1818 1819 1820
		/* record current link speed */
		if (sata_scr_read(ap, SCR_STATUS, &sstatus) == 0)
			ap->sata_spd = (sstatus >> 4) & 0xf;

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1821 1822 1823 1824
		if (postreset)
			postreset(ap, classes);

		/* reset successful, schedule revalidation */
1825
		ata_eh_done(ap, NULL, ehc->i.action & ATA_EH_RESET_MASK);
T
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1826 1827
		ehc->i.action |= ATA_EH_REVALIDATE;
	}
1828 1829 1830
 out:
	/* clear hotplug flag */
	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
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1831 1832 1833
	return rc;
}

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1834 1835
static int ata_eh_revalidate_and_attach(struct ata_port *ap,
					struct ata_device **r_failed_dev)
T
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1836 1837 1838
{
	struct ata_eh_context *ehc = &ap->eh_context;
	struct ata_device *dev;
1839
	unsigned int new_mask = 0;
T
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1840
	unsigned long flags;
T
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1841 1842 1843 1844
	int i, rc = 0;

	DPRINTK("ENTER\n");

1845 1846 1847 1848 1849
	/* For PATA drive side cable detection to work, IDENTIFY must
	 * be done backwards such that PDIAG- is released by the slave
	 * device before the master device is identified.
	 */
	for (i = ATA_MAX_DEVICES - 1; i >= 0; i--) {
1850
		unsigned int action, readid_flags = 0;
1851

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		dev = &ap->device[i];
1853
		action = ata_eh_dev_action(dev);
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1855 1856 1857
		if (ehc->i.flags & ATA_EHI_DID_RESET)
			readid_flags |= ATA_READID_POSTRESET;

1858
		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
T
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1859 1860
			if (ata_port_offline(ap)) {
				rc = -EIO;
1861
				goto err;
T
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1862 1863
			}

1864
			ata_eh_about_to_do(ap, dev, ATA_EH_REVALIDATE);
1865
			rc = ata_dev_revalidate(dev, readid_flags);
T
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1866
			if (rc)
1867
				goto err;
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1868

1869 1870
			ata_eh_done(ap, dev, ATA_EH_REVALIDATE);

1871 1872 1873 1874 1875
			/* Configuration may have changed, reconfigure
			 * transfer mode.
			 */
			ehc->i.flags |= ATA_EHI_SETMODE;

1876 1877
			/* schedule the scsi_rescan_device() here */
			queue_work(ata_aux_wq, &(ap->scsi_rescan_task));
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1878 1879 1880 1881 1882
		} else if (dev->class == ATA_DEV_UNKNOWN &&
			   ehc->tries[dev->devno] &&
			   ata_class_enabled(ehc->classes[dev->devno])) {
			dev->class = ehc->classes[dev->devno];

1883 1884
			rc = ata_dev_read_id(dev, &dev->class, readid_flags,
					     dev->id);
1885 1886 1887 1888 1889
			switch (rc) {
			case 0:
				new_mask |= 1 << i;
				break;
			case -ENOENT:
1890 1891 1892 1893 1894
				/* IDENTIFY was issued to non-existent
				 * device.  No need to reset.  Just
				 * thaw and kill the device.
				 */
				ata_eh_thaw_port(ap);
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1895 1896
				dev->class = ATA_DEV_UNKNOWN;
				break;
1897 1898 1899
			default:
				dev->class = ATA_DEV_UNKNOWN;
				goto err;
T
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1900
			}
1901 1902
		}
	}
T
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1903

1904 1905 1906 1907
	/* PDIAG- should have been released, ask cable type if post-reset */
	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ap->ops->cable_detect)
		ap->cbl = ap->ops->cable_detect(ap);

1908 1909 1910 1911 1912
	/* Configure new devices forward such that user doesn't see
	 * device detection messages backwards.
	 */
	for (i = 0; i < ATA_MAX_DEVICES; i++) {
		dev = &ap->device[i];
1913

1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928
		if (!(new_mask & (1 << i)))
			continue;

		ehc->i.flags |= ATA_EHI_PRINTINFO;
		rc = ata_dev_configure(dev);
		ehc->i.flags &= ~ATA_EHI_PRINTINFO;
		if (rc)
			goto err;

		spin_lock_irqsave(ap->lock, flags);
		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
		spin_unlock_irqrestore(ap->lock, flags);

		/* new device discovered, configure xfermode */
		ehc->i.flags |= ATA_EHI_SETMODE;
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1929 1930
	}

1931
	return 0;
T
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1932

1933 1934 1935
 err:
	*r_failed_dev = dev;
	DPRINTK("EXIT rc=%d\n", rc);
T
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1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948
	return rc;
}

static int ata_port_nr_enabled(struct ata_port *ap)
{
	int i, cnt = 0;

	for (i = 0; i < ATA_MAX_DEVICES; i++)
		if (ata_dev_enabled(&ap->device[i]))
			cnt++;
	return cnt;
}

T
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1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963
static int ata_port_nr_vacant(struct ata_port *ap)
{
	int i, cnt = 0;

	for (i = 0; i < ATA_MAX_DEVICES; i++)
		if (ap->device[i].class == ATA_DEV_UNKNOWN)
			cnt++;
	return cnt;
}

static int ata_eh_skip_recovery(struct ata_port *ap)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	int i;

1964 1965 1966
	/* thaw frozen port, resume link and recover failed devices */
	if ((ap->pflags & ATA_PFLAG_FROZEN) ||
	    (ehc->i.flags & ATA_EHI_RESUME_LINK) || ata_port_nr_enabled(ap))
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1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980
		return 0;

	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
	for (i = 0; i < ATA_MAX_DEVICES; i++) {
		struct ata_device *dev = &ap->device[i];

		if (dev->class == ATA_DEV_UNKNOWN &&
		    ehc->classes[dev->devno] != ATA_DEV_NONE)
			return 0;
	}

	return 1;
}

1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031
static void ata_eh_handle_dev_fail(struct ata_device *dev, int err)
{
	struct ata_port *ap = dev->ap;
	struct ata_eh_context *ehc = &ap->eh_context;

	ehc->tries[dev->devno]--;

	switch (err) {
	case -ENODEV:
		/* device missing or wrong IDENTIFY data, schedule probing */
		ehc->i.probe_mask |= (1 << dev->devno);
	case -EINVAL:
		/* give it just one more chance */
		ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
	case -EIO:
		if (ehc->tries[dev->devno] == 1) {
			/* This is the last chance, better to slow
			 * down than lose it.
			 */
			sata_down_spd_limit(ap);
			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
		}
	}

	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
		/* disable device if it has used up all its chances */
		ata_dev_disable(dev);

		/* detach if offline */
		if (ata_port_offline(ap))
			ata_eh_detach_dev(dev);

		/* probe if requested */
		if ((ehc->i.probe_mask & (1 << dev->devno)) &&
		    !(ehc->did_probe_mask & (1 << dev->devno))) {
			ata_eh_detach_dev(dev);
			ata_dev_init(dev);

			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
			ehc->did_probe_mask |= (1 << dev->devno);
			ehc->i.action |= ATA_EH_SOFTRESET;
		}
	} else {
		/* soft didn't work?  be haaaaard */
		if (ehc->i.flags & ATA_EHI_DID_RESET)
			ehc->i.action |= ATA_EH_HARDRESET;
		else
			ehc->i.action |= ATA_EH_SOFTRESET;
	}
}

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2032 2033 2034
/**
 *	ata_eh_recover - recover host port after error
 *	@ap: host port to recover
2035
 *	@prereset: prereset method (can be NULL)
T
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2036 2037 2038 2039 2040 2041
 *	@softreset: softreset method (can be NULL)
 *	@hardreset: hardreset method (can be NULL)
 *	@postreset: postreset method (can be NULL)
 *
 *	This is the alpha and omega, eum and yang, heart and soul of
 *	libata exception handling.  On entry, actions required to
T
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2042 2043 2044 2045
 *	recover the port and hotplug requests are recorded in
 *	eh_context.  This function executes all the operations with
 *	appropriate retrials and fallbacks to resurrect failed
 *	devices, detach goners and greet newcomers.
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2046 2047 2048 2049 2050 2051 2052
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 *
 *	RETURNS:
 *	0 on success, -errno on failure.
 */
2053 2054
static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
			  ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
T
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2055 2056 2057 2058
			  ata_postreset_fn_t postreset)
{
	struct ata_eh_context *ehc = &ap->eh_context;
	struct ata_device *dev;
2059
	int i, rc;
T
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2060 2061 2062 2063 2064 2065 2066 2067

	DPRINTK("ENTER\n");

	/* prep for recovery */
	for (i = 0; i < ATA_MAX_DEVICES; i++) {
		dev = &ap->device[i];

		ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
T
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2068

2069 2070 2071 2072
		/* collect port action mask recorded in dev actions */
		ehc->i.action |= ehc->i.dev_action[i] & ~ATA_EH_PERDEV_MASK;
		ehc->i.dev_action[i] &= ATA_EH_PERDEV_MASK;

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2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084
		/* process hotplug request */
		if (dev->flags & ATA_DFLAG_DETACH)
			ata_eh_detach_dev(dev);

		if (!ata_dev_enabled(dev) &&
		    ((ehc->i.probe_mask & (1 << dev->devno)) &&
		     !(ehc->did_probe_mask & (1 << dev->devno)))) {
			ata_eh_detach_dev(dev);
			ata_dev_init(dev);
			ehc->did_probe_mask |= (1 << dev->devno);
			ehc->i.action |= ATA_EH_SOFTRESET;
		}
T
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2085 2086 2087 2088 2089
	}

 retry:
	rc = 0;

2090
	/* if UNLOADING, finish immediately */
2091
	if (ap->pflags & ATA_PFLAG_UNLOADING)
2092 2093
		goto out;

T
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2094
	/* skip EH if possible. */
T
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2095
	if (ata_eh_skip_recovery(ap))
T
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2096 2097
		ehc->i.action = 0;

T
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2098 2099 2100
	for (i = 0; i < ATA_MAX_DEVICES; i++)
		ehc->classes[i] = ATA_DEV_UNKNOWN;

T
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2101 2102 2103 2104
	/* reset */
	if (ehc->i.action & ATA_EH_RESET_MASK) {
		ata_eh_freeze_port(ap);

T
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2105 2106
		rc = ata_eh_reset(ap, ata_port_nr_vacant(ap), prereset,
				  softreset, hardreset, postreset);
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2107 2108 2109 2110 2111 2112 2113 2114 2115
		if (rc) {
			ata_port_printk(ap, KERN_ERR,
					"reset failed, giving up\n");
			goto out;
		}

		ata_eh_thaw_port(ap);
	}

T
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2116 2117
	/* revalidate existing devices and attach new ones */
	rc = ata_eh_revalidate_and_attach(ap, &dev);
T
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2118 2119 2120
	if (rc)
		goto dev_fail;

2121 2122
	/* configure transfer mode if necessary */
	if (ehc->i.flags & ATA_EHI_SETMODE) {
T
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2123
		rc = ata_set_mode(ap, &dev);
2124
		if (rc)
T
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2125
			goto dev_fail;
2126
		ehc->i.flags &= ~ATA_EHI_SETMODE;
T
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2127 2128 2129 2130 2131
	}

	goto out;

 dev_fail:
2132
	ata_eh_handle_dev_fail(dev, rc);
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2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199

	if (ata_port_nr_enabled(ap)) {
		ata_port_printk(ap, KERN_WARNING, "failed to recover some "
				"devices, retrying in 5 secs\n");
		ssleep(5);
	} else {
		/* no device left, repeat fast */
		msleep(500);
	}

	goto retry;

 out:
	if (rc) {
		for (i = 0; i < ATA_MAX_DEVICES; i++)
			ata_dev_disable(&ap->device[i]);
	}

	DPRINTK("EXIT, rc=%d\n", rc);
	return rc;
}

/**
 *	ata_eh_finish - finish up EH
 *	@ap: host port to finish EH for
 *
 *	Recovery is complete.  Clean up EH states and retry or finish
 *	failed qcs.
 *
 *	LOCKING:
 *	None.
 */
static void ata_eh_finish(struct ata_port *ap)
{
	int tag;

	/* retry or finish qcs */
	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);

		if (!(qc->flags & ATA_QCFLAG_FAILED))
			continue;

		if (qc->err_mask) {
			/* FIXME: Once EH migration is complete,
			 * generate sense data in this function,
			 * considering both err_mask and tf.
			 */
			if (qc->err_mask & AC_ERR_INVALID)
				ata_eh_qc_complete(qc);
			else
				ata_eh_qc_retry(qc);
		} else {
			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
				ata_eh_qc_complete(qc);
			} else {
				/* feed zero TF to sense generation */
				memset(&qc->result_tf, 0, sizeof(qc->result_tf));
				ata_eh_qc_retry(qc);
			}
		}
	}
}

/**
 *	ata_do_eh - do standard error handling
 *	@ap: host port to handle error for
2200
 *	@prereset: prereset method (can be NULL)
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2201 2202 2203 2204 2205 2206 2207 2208 2209
 *	@softreset: softreset method (can be NULL)
 *	@hardreset: hardreset method (can be NULL)
 *	@postreset: postreset method (can be NULL)
 *
 *	Perform standard error handling sequence.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
2210 2211 2212
void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
	       ata_postreset_fn_t postreset)
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2213
{
2214 2215
	ata_eh_autopsy(ap);
	ata_eh_report(ap);
2216
	ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
T
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2217 2218
	ata_eh_finish(ap);
}
2219

2220
#ifdef CONFIG_PM
2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245
/**
 *	ata_eh_handle_port_suspend - perform port suspend operation
 *	@ap: port to suspend
 *
 *	Suspend @ap.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_handle_port_suspend(struct ata_port *ap)
{
	unsigned long flags;
	int rc = 0;

	/* are we suspending? */
	spin_lock_irqsave(ap->lock, flags);
	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
	    ap->pm_mesg.event == PM_EVENT_ON) {
		spin_unlock_irqrestore(ap->lock, flags);
		return;
	}
	spin_unlock_irqrestore(ap->lock, flags);

	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);

2246 2247 2248 2249 2250
	/* tell ACPI we're suspending */
	rc = ata_acpi_on_suspend(ap);
	if (rc)
		goto out;

2251 2252 2253 2254 2255 2256
	/* suspend */
	ata_eh_freeze_port(ap);

	if (ap->ops->port_suspend)
		rc = ap->ops->port_suspend(ap, ap->pm_mesg);

2257
 out:
2258 2259 2260 2261 2262 2263
	/* report result */
	spin_lock_irqsave(ap->lock, flags);

	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
	if (rc == 0)
		ap->pflags |= ATA_PFLAG_SUSPENDED;
2264
	else if (ap->pflags & ATA_PFLAG_FROZEN)
2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
		ata_port_schedule_eh(ap);

	if (ap->pm_result) {
		*ap->pm_result = rc;
		ap->pm_result = NULL;
	}

	spin_unlock_irqrestore(ap->lock, flags);

	return;
}

/**
 *	ata_eh_handle_port_resume - perform port resume operation
 *	@ap: port to resume
 *
 *	Resume @ap.
 *
 *	LOCKING:
 *	Kernel thread context (may sleep).
 */
static void ata_eh_handle_port_resume(struct ata_port *ap)
{
	unsigned long flags;
2289
	int rc = 0;
2290 2291 2292 2293 2294 2295 2296 2297 2298 2299

	/* are we resuming? */
	spin_lock_irqsave(ap->lock, flags);
	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
	    ap->pm_mesg.event != PM_EVENT_ON) {
		spin_unlock_irqrestore(ap->lock, flags);
		return;
	}
	spin_unlock_irqrestore(ap->lock, flags);

2300
	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
2301 2302 2303 2304

	if (ap->ops->port_resume)
		rc = ap->ops->port_resume(ap);

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2305 2306 2307
	/* tell ACPI that we're resuming */
	ata_acpi_on_resume(ap);

2308
	/* report result */
2309 2310 2311 2312 2313 2314 2315 2316
	spin_lock_irqsave(ap->lock, flags);
	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
	if (ap->pm_result) {
		*ap->pm_result = rc;
		ap->pm_result = NULL;
	}
	spin_unlock_irqrestore(ap->lock, flags);
}
2317
#endif /* CONFIG_PM */