X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=drivers%2Fscsi%2Flibata-eh.c;h=bf5a72aca8a4979957ae9a7ce8ff519d70490655;hb=55b4d6a52195a8f277ffddf755ddaff359878f41;hp=9173d8f2ce5db7e999211e03f3509895cb0e2a9a;hpb=c6cf9e99d1de5ca6a08fb639bb73031ffe50d802;p=linux-2.6-block.git

diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 9173d8f2ce5d..bf5a72aca8a4 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -46,6 +46,7 @@
 #include "libata.h"
 
 static void __ata_port_freeze(struct ata_port *ap);
+static void ata_eh_finish(struct ata_port *ap);
 
 static void ata_ering_record(struct ata_ering *ering, int is_io,
 			     unsigned int err_mask)
@@ -92,6 +93,38 @@ static int ata_ering_map(struct ata_ering *ering,
 	return rc;
 }
 
+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];
+}
+
+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;
+	}
+}
+
 /**
  *	ata_scsi_timed_out - SCSI layer time out callback
  *	@cmd: timed out SCSI command
@@ -127,7 +160,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 	}
 
 	ret = EH_HANDLED;
-	spin_lock_irqsave(&ap->host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 	qc = ata_qc_from_tag(ap, ap->active_tag);
 	if (qc) {
 		WARN_ON(qc->scsicmd != cmd);
@@ -135,7 +168,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 		qc->err_mask |= AC_ERR_TIMEOUT;
 		ret = EH_NOT_HANDLED;
 	}
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 
  out:
 	DPRINTK("EXIT, ret=%d\n", ret);
@@ -157,7 +190,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 void ata_scsi_error(struct Scsi_Host *host)
 {
 	struct ata_port *ap = ata_shost_to_port(host);
-	spinlock_t *hs_lock = &ap->host_set->lock;
+	spinlock_t *ap_lock = ap->lock;
 	int i, repeat_cnt = ATA_EH_MAX_REPEAT;
 	unsigned long flags;
 
@@ -184,7 +217,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 		struct scsi_cmnd *scmd, *tmp;
 		int nr_timedout = 0;
 
-		spin_lock_irqsave(hs_lock, flags);
+		spin_lock_irqsave(ap_lock, flags);
 
 		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
 			struct ata_queued_cmd *qc;
@@ -223,15 +256,15 @@ void ata_scsi_error(struct Scsi_Host *host)
 		if (nr_timedout)
 			__ata_port_freeze(ap);
 
-		spin_unlock_irqrestore(hs_lock, flags);
+		spin_unlock_irqrestore(ap_lock, flags);
 	} else
-		spin_unlock_wait(hs_lock);
+		spin_unlock_wait(ap_lock);
 
  repeat:
 	/* invoke error handler */
 	if (ap->ops->error_handler) {
 		/* fetch & clear EH info */
-		spin_lock_irqsave(hs_lock, flags);
+		spin_lock_irqsave(ap_lock, flags);
 
 		memset(&ap->eh_context, 0, sizeof(ap->eh_context));
 		ap->eh_context.i = ap->eh_info;
@@ -240,23 +273,26 @@ void ata_scsi_error(struct Scsi_Host *host)
 		ap->flags |= ATA_FLAG_EH_IN_PROGRESS;
 		ap->flags &= ~ATA_FLAG_EH_PENDING;
 
-		spin_unlock_irqrestore(hs_lock, flags);
+		spin_unlock_irqrestore(ap_lock, flags);
 
-		/* invoke EH */
-		ap->ops->error_handler(ap);
+		/* invoke EH.  if unloading, just finish failed qcs */
+		if (!(ap->flags & ATA_FLAG_UNLOADING))
+			ap->ops->error_handler(ap);
+		else
+			ata_eh_finish(ap);
 
 		/* Exception might have happend after ->error_handler
 		 * recovered the port but before this point.  Repeat
 		 * EH in such case.
 		 */
-		spin_lock_irqsave(hs_lock, flags);
+		spin_lock_irqsave(ap_lock, flags);
 
 		if (ap->flags & ATA_FLAG_EH_PENDING) {
 			if (--repeat_cnt) {
 				ata_port_printk(ap, KERN_INFO,
 					"EH pending after completion, "
 					"repeating EH (cnt=%d)\n", repeat_cnt);
-				spin_unlock_irqrestore(hs_lock, flags);
+				spin_unlock_irqrestore(ap_lock, flags);
 				goto repeat;
 			}
 			ata_port_printk(ap, KERN_ERR, "EH pending after %d "
@@ -266,14 +302,14 @@ void ata_scsi_error(struct Scsi_Host *host)
 		/* this run is complete, make sure EH info is clear */
 		memset(&ap->eh_info, 0, sizeof(ap->eh_info));
 
-		/* Clear host_eh_scheduled while holding hs_lock such
+		/* Clear host_eh_scheduled while holding ap_lock such
 		 * that if exception occurs after this point but
 		 * before EH completion, SCSI midlayer will
 		 * re-initiate EH.
 		 */
 		host->host_eh_scheduled = 0;
 
-		spin_unlock_irqrestore(hs_lock, flags);
+		spin_unlock_irqrestore(ap_lock, flags);
 	} else {
 		WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL);
 		ap->ops->eng_timeout(ap);
@@ -285,17 +321,24 @@ void ata_scsi_error(struct Scsi_Host *host)
 	scsi_eh_flush_done_q(&ap->eh_done_q);
 
 	/* clean up */
-	spin_lock_irqsave(hs_lock, flags);
+	spin_lock_irqsave(ap_lock, flags);
+
+	if (ap->flags & ATA_FLAG_LOADING) {
+		ap->flags &= ~ATA_FLAG_LOADING;
+	} else {
+		if (ap->flags & ATA_FLAG_SCSI_HOTPLUG)
+			queue_work(ata_aux_wq, &ap->hotplug_task);
+		if (ap->flags & ATA_FLAG_RECOVERED)
+			ata_port_printk(ap, KERN_INFO, "EH complete\n");
+	}
 
-	if (ap->flags & ATA_FLAG_RECOVERED)
-		ata_port_printk(ap, KERN_INFO, "EH complete\n");
-	ap->flags &= ~ATA_FLAG_RECOVERED;
+	ap->flags &= ~(ATA_FLAG_SCSI_HOTPLUG | ATA_FLAG_RECOVERED);
 
 	/* tell wait_eh that we're done */
 	ap->flags &= ~ATA_FLAG_EH_IN_PROGRESS;
 	wake_up_all(&ap->eh_wait_q);
 
-	spin_unlock_irqrestore(hs_lock, flags);
+	spin_unlock_irqrestore(ap_lock, flags);
 
 	DPRINTK("EXIT\n");
 }
@@ -315,16 +358,17 @@ void ata_port_wait_eh(struct ata_port *ap)
 	DEFINE_WAIT(wait);
 
  retry:
-	spin_lock_irqsave(&ap->host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 
 	while (ap->flags & (ATA_FLAG_EH_PENDING | ATA_FLAG_EH_IN_PROGRESS)) {
 		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock_irqrestore(&ap->host_set->lock, flags);
+		spin_unlock_irqrestore(ap->lock, flags);
 		schedule();
-		spin_lock_irqsave(&ap->host_set->lock, flags);
+		spin_lock_irqsave(ap->lock, flags);
 	}
+	finish_wait(&ap->eh_wait_q, &wait);
 
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 
 	/* make sure SCSI EH is complete */
 	if (scsi_host_in_recovery(ap->host)) {
@@ -356,7 +400,6 @@ void ata_port_wait_eh(struct ata_port *ap)
 static void ata_qc_timeout(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
-	struct ata_host_set *host_set = ap->host_set;
 	u8 host_stat = 0, drv_stat;
 	unsigned long flags;
 
@@ -364,7 +407,7 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
 
 	ap->hsm_task_state = HSM_ST_IDLE;
 
-	spin_lock_irqsave(&host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 
 	switch (qc->tf.protocol) {
 
@@ -393,7 +436,7 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
 		break;
 	}
 
-	spin_unlock_irqrestore(&host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 
 	ata_eh_qc_complete(qc);
 
@@ -580,9 +623,9 @@ void ata_eh_freeze_port(struct ata_port *ap)
 	if (!ap->ops->error_handler)
 		return;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 	__ata_port_freeze(ap);
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 }
 
 /**
@@ -601,14 +644,14 @@ void ata_eh_thaw_port(struct ata_port *ap)
 	if (!ap->ops->error_handler)
 		return;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 
 	ap->flags &= ~ATA_FLAG_FROZEN;
 
 	if (ap->ops->thaw)
 		ap->ops->thaw(ap);
 
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 
 	DPRINTK("ata%u port thawed\n", ap->id);
 }
@@ -624,11 +667,11 @@ static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	unsigned long flags;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
+	spin_lock_irqsave(ap->lock, flags);
 	qc->scsidone = ata_eh_scsidone;
 	__ata_qc_complete(qc);
 	WARN_ON(ata_tag_valid(qc->tag));
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
 
 	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
 }
@@ -666,9 +709,42 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc)
 	__ata_eh_qc_complete(qc);
 }
 
+/**
+ *	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);
+
+	spin_lock_irqsave(ap->lock, flags);
+
+	dev->flags &= ~ATA_DFLAG_DETACH;
+
+	if (ata_scsi_offline_dev(dev)) {
+		dev->flags |= ATA_DFLAG_DETACHED;
+		ap->flags |= ATA_FLAG_SCSI_HOTPLUG;
+	}
+
+	/* 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);
+
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
 /**
  *	ata_eh_about_to_do - about to perform eh_action
  *	@ap: target ATA port
+ *	@dev: target ATA dev for per-dev action (can be NULL)
  *	@action: action about to be performed
  *
  *	Called just before performing EH actions to clear related bits
@@ -678,14 +754,33 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc)
  *	LOCKING:
  *	None.
  */
-static void ata_eh_about_to_do(struct ata_port *ap, unsigned int action)
+static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
+			       unsigned int action)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
-	ap->eh_info.action &= ~action;
+	spin_lock_irqsave(ap->lock, flags);
+	ata_eh_clear_action(dev, &ap->eh_info, action);
 	ap->flags |= ATA_FLAG_RECOVERED;
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	spin_unlock_irqrestore(ap->lock, flags);
+}
+
+/**
+ *	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)
+{
+	ata_eh_clear_action(dev, &ap->eh_context.i, action);
 }
 
 /**
@@ -904,10 +999,8 @@ static void ata_eh_analyze_serror(struct ata_port *ap)
 		err_mask |= AC_ERR_SYSTEM;
 		action |= ATA_EH_SOFTRESET;
 	}
-	if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG)) {
-		err_mask |= AC_ERR_ATA_BUS;
-		action |= ATA_EH_HARDRESET;
-	}
+	if (serror & (SERR_PHYRDY_CHG | SERR_DEV_XCHG))
+		ata_ehi_hotplugged(&ehc->i);
 
 	ehc->i.err_mask |= err_mask;
 	ehc->i.action |= action;
@@ -1233,10 +1326,6 @@ static void ata_eh_autopsy(struct ata_port *ap)
 			is_io = 1;
 	}
 
-	/* speed down iff command was in progress */
-	if (failed_dev)
-		action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask);
-
 	/* enforce default EH actions */
 	if (ap->flags & ATA_FLAG_FROZEN ||
 	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
@@ -1244,6 +1333,17 @@ static void ata_eh_autopsy(struct ata_port *ap)
 	else if (all_err_mask)
 		action |= ATA_EH_REVALIDATE;
 
+	/* if we have offending qcs and the associated failed device */
+	if (failed_dev) {
+		/* speed down */
+		action |= ata_eh_speed_down(failed_dev, is_io, all_err_mask);
+
+		/* perform per-dev EH action only on the offending device */
+		ehc->i.dev_action[failed_dev->devno] |=
+			action & ATA_EH_PERDEV_MASK;
+		action &= ~ATA_EH_PERDEV_MASK;
+	}
+
 	/* record autopsy result */
 	ehc->i.dev = failed_dev;
 	ehc->i.action = action;
@@ -1318,35 +1418,150 @@ static void ata_eh_report(struct ata_port *ap)
 	}
 }
 
-static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset,
+static int ata_do_reset(struct ata_port *ap, ata_reset_fn_t reset,
+			unsigned int *classes)
+{
+	int i, rc;
+
+	for (i = 0; i < ATA_MAX_DEVICES; i++)
+		classes[i] = ATA_DEV_UNKNOWN;
+
+	rc = reset(ap, classes);
+	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;
+}
+
+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,
+			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
-	unsigned int classes[ATA_MAX_DEVICES];
+	unsigned int *classes = ehc->classes;
 	int tries = ATA_EH_RESET_TRIES;
+	int verbose = !(ap->flags & ATA_FLAG_LOADING);
+	unsigned int action;
 	ata_reset_fn_t reset;
-	int i, rc;
+	int i, did_followup_srst, rc;
 
+	/* 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;
 	if (softreset && (!hardreset || (!sata_set_spd_needed(ap) &&
-					 !(ehc->i.action & ATA_EH_HARDRESET))))
-		reset = softreset;
+					 !(action & ATA_EH_HARDRESET))))
+		ehc->i.action |= ATA_EH_SOFTRESET;
 	else
+		ehc->i.action |= ATA_EH_HARDRESET;
+
+	if (prereset) {
+		rc = prereset(ap);
+		if (rc) {
+			ata_port_printk(ap, KERN_ERR,
+					"prereset failed (errno=%d)\n", rc);
+			return rc;
+		}
+	}
+
+	/* prereset() might have modified ehc->i.action */
+	if (ehc->i.action & ATA_EH_HARDRESET)
 		reset = hardreset;
+	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;
+		return 0;
+	}
+
+	/* did prereset() screw up?  if so, fix up to avoid oopsing */
+	if (!reset) {
+		ata_port_printk(ap, KERN_ERR, "BUG: prereset() requested "
+				"invalid reset type\n");
+		if (softreset)
+			reset = softreset;
+		else
+			reset = hardreset;
+	}
 
  retry:
-	ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
-			reset == softreset ? "soft" : "hard");
+	/* shut up during boot probing */
+	if (verbose)
+		ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
+				reset == softreset ? "soft" : "hard");
 
 	/* reset */
-	ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
+	ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK);
 	ehc->i.flags |= ATA_EHI_DID_RESET;
 
 	rc = ata_do_reset(ap, reset, classes);
 
+	did_followup_srst = 0;
+	if (reset == hardreset &&
+	    ata_eh_followup_srst_needed(rc, classify, classes)) {
+		/* okay, let's do follow-up softreset */
+		did_followup_srst = 1;
+		reset = softreset;
+
+		if (!reset) {
+			ata_port_printk(ap, KERN_ERR,
+					"follow-up softreset required "
+					"but no softreset avaliable\n");
+			return -EINVAL;
+		}
+
+		ata_eh_about_to_do(ap, NULL, ATA_EH_RESET_MASK);
+		rc = ata_do_reset(ap, reset, classes);
+
+		if (rc == 0 && classify &&
+		    classes[0] == ATA_DEV_UNKNOWN) {
+			ata_port_printk(ap, KERN_ERR,
+					"classification failed\n");
+			return -EINVAL;
+		}
+	}
+
 	if (rc && --tries) {
+		const char *type;
+
+		if (reset == softreset) {
+			if (did_followup_srst)
+				type = "follow-up soft";
+			else
+				type = "soft";
+		} else
+			type = "hard";
+
 		ata_port_printk(ap, KERN_WARNING,
-				"%sreset failed, retrying in 5 secs\n",
-				reset == softreset ? "soft" : "hard");
+				"%sreset failed, retrying in 5 secs\n", type);
 		ssleep(5);
 
 		if (reset == hardreset)
@@ -1367,40 +1582,62 @@ static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset,
 			postreset(ap, classes);
 
 		/* reset successful, schedule revalidation */
-		ehc->i.dev = NULL;
-		ehc->i.action &= ~ATA_EH_RESET_MASK;
+		ata_eh_done(ap, NULL, ATA_EH_RESET_MASK);
 		ehc->i.action |= ATA_EH_REVALIDATE;
 	}
 
 	return rc;
 }
 
-static int ata_eh_revalidate(struct ata_port *ap,
-			     struct ata_device **r_failed_dev)
+static int ata_eh_revalidate_and_attach(struct ata_port *ap,
+					struct ata_device **r_failed_dev)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
 	struct ata_device *dev;
+	unsigned long flags;
 	int i, rc = 0;
 
 	DPRINTK("ENTER\n");
 
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
+		unsigned int action;
+
 		dev = &ap->device[i];
+		action = ata_eh_dev_action(dev);
 
-		if (ehc->i.action & ATA_EH_REVALIDATE && ata_dev_enabled(dev) &&
-		    (!ehc->i.dev || ehc->i.dev == dev)) {
+		if (action & ATA_EH_REVALIDATE && ata_dev_enabled(dev)) {
 			if (ata_port_offline(ap)) {
 				rc = -EIO;
 				break;
 			}
 
-			ata_eh_about_to_do(ap, ATA_EH_REVALIDATE);
+			ata_eh_about_to_do(ap, dev, ATA_EH_REVALIDATE);
 			rc = ata_dev_revalidate(dev,
 					ehc->i.flags & ATA_EHI_DID_RESET);
 			if (rc)
 				break;
 
-			ehc->i.action &= ~ATA_EH_REVALIDATE;
+			ata_eh_done(ap, dev, ATA_EH_REVALIDATE);
+
+			/* schedule the scsi_rescan_device() here */
+			queue_work(ata_aux_wq, &(ap->scsi_rescan_task));
+		} else if (dev->class == ATA_DEV_UNKNOWN &&
+			   ehc->tries[dev->devno] &&
+			   ata_class_enabled(ehc->classes[dev->devno])) {
+			dev->class = ehc->classes[dev->devno];
+
+			rc = ata_dev_read_id(dev, &dev->class, 1, dev->id);
+			if (rc == 0)
+				rc = ata_dev_configure(dev, 1);
+
+			if (rc) {
+				dev->class = ATA_DEV_UNKNOWN;
+				break;
+			}
+
+			spin_lock_irqsave(ap->lock, flags);
+			ap->flags |= ATA_FLAG_SCSI_HOTPLUG;
+			spin_unlock_irqrestore(ap->lock, flags);
 		}
 	}
 
@@ -1421,18 +1658,50 @@ static int ata_port_nr_enabled(struct ata_port *ap)
 	return cnt;
 }
 
+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;
+
+	if (ap->flags & ATA_FLAG_FROZEN || ata_port_nr_enabled(ap))
+		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;
+}
+
 /**
  *	ata_eh_recover - recover host port after error
  *	@ap: host port to recover
+ *	@prereset: prereset method (can be NULL)
  *	@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
- *	recover each devices are recorded in eh_context.  This
- *	function executes all the operations with appropriate retrials
- *	and fallbacks to resurrect failed devices.
+ *	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.
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).
@@ -1440,8 +1709,8 @@ static int ata_port_nr_enabled(struct ata_port *ap)
  *	RETURNS:
  *	0 on success, -errno on failure.
  */
-static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
-			  ata_reset_fn_t hardreset,
+static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
+			  ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
 			  ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
@@ -1455,21 +1724,42 @@ static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
 		dev = &ap->device[i];
 
 		ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
+
+		/* 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;
+		}
 	}
 
  retry:
 	down_xfermask = 0;
 	rc = 0;
 
+	/* if UNLOADING, finish immediately */
+	if (ap->flags & ATA_FLAG_UNLOADING)
+		goto out;
+
 	/* skip EH if possible. */
-	if (!ata_port_nr_enabled(ap) && !(ap->flags & ATA_FLAG_FROZEN))
+	if (ata_eh_skip_recovery(ap))
 		ehc->i.action = 0;
 
+	for (i = 0; i < ATA_MAX_DEVICES; i++)
+		ehc->classes[i] = ATA_DEV_UNKNOWN;
+
 	/* reset */
 	if (ehc->i.action & ATA_EH_RESET_MASK) {
 		ata_eh_freeze_port(ap);
 
-		rc = ata_eh_reset(ap, softreset, hardreset, postreset);
+		rc = ata_eh_reset(ap, ata_port_nr_vacant(ap), prereset,
+				  softreset, hardreset, postreset);
 		if (rc) {
 			ata_port_printk(ap, KERN_ERR,
 					"reset failed, giving up\n");
@@ -1479,8 +1769,8 @@ static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
 		ata_eh_thaw_port(ap);
 	}
 
-	/* revalidate existing devices */
-	rc = ata_eh_revalidate(ap, &dev);
+	/* revalidate existing devices and attach new ones */
+	rc = ata_eh_revalidate_and_attach(ap, &dev);
 	if (rc)
 		goto dev_fail;
 
@@ -1498,6 +1788,8 @@ static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
  dev_fail:
 	switch (rc) {
 	case -ENODEV:
+		/* device missing, schedule probing */
+		ehc->i.probe_mask |= (1 << dev->devno);
 	case -EINVAL:
 		ehc->tries[dev->devno] = 0;
 		break;
@@ -1510,15 +1802,31 @@ static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
 			ehc->tries[dev->devno] = 0;
 	}
 
-	/* disable device if it has used up all its chances */
-	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno])
+	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
+		/* disable device if it has used up all its chances */
 		ata_dev_disable(dev);
 
-	/* 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;
+		/* 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;
+	}
 
 	if (ata_port_nr_enabled(ap)) {
 		ata_port_printk(ap, KERN_WARNING, "failed to recover some "
@@ -1586,6 +1894,7 @@ static void ata_eh_finish(struct ata_port *ap)
 /**
  *	ata_do_eh - do standard error handling
  *	@ap: host port to handle error for
+ *	@prereset: prereset method (can be NULL)
  *	@softreset: softreset method (can be NULL)
  *	@hardreset: hardreset method (can be NULL)
  *	@postreset: postreset method (can be NULL)
@@ -1595,11 +1904,15 @@ static void ata_eh_finish(struct ata_port *ap)
  *	LOCKING:
  *	Kernel thread context (may sleep).
  */
-void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset,
-	       ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+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)
 {
-	ata_eh_autopsy(ap);
-	ata_eh_report(ap);
-	ata_eh_recover(ap, softreset, hardreset, postreset);
+	if (!(ap->flags & ATA_FLAG_LOADING)) {
+		ata_eh_autopsy(ap);
+		ata_eh_report(ap);
+	}
+
+	ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
 	ata_eh_finish(ap);
 }