Merge ../linus
[linux-2.6-block.git] / drivers / scsi / libata-eh.c
index 9173d8f2ce5db7e999211e03f3509895cb0e2a9a..bf5a72aca8a4979957ae9a7ce8ff519d70490655 100644 (file)
@@ -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);
 }