diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index a049bffdf7705e279429b37a58adff59920c58c4..b53e2e7db498a5a2155302babf40ed7bf40f33a0 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -932,10 +932,8 @@ 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;
@@ -1487,11 +1485,12 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
 	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");
@@ -1513,6 +1512,23 @@ static int ata_eh_revalidate(struct ata_port *ap,
 				break;
 
 			ehc->i.action &= ~ATA_EH_REVALIDATE;
+		} 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->host_set->lock, flags);
+			ap->flags |= ATA_FLAG_SCSI_HOTPLUG;
+			spin_unlock_irqrestore(&ap->host_set->lock, flags);
 		}
 	}
 
@@ -1533,6 +1549,36 @@ 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
@@ -1543,9 +1589,10 @@ static int ata_port_nr_enabled(struct ata_port *ap)
  *
  *	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).
@@ -1568,6 +1615,19 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		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:
@@ -1575,15 +1635,18 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 	rc = 0;
 
 	/* 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, 0, prereset, 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");
@@ -1593,8 +1656,8 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 		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;
 
@@ -1612,6 +1675,8 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
  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;
@@ -1624,15 +1689,31 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 			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 "
diff --git a/include/linux/libata.h b/include/linux/libata.h
index a1ceb5b67b97729c0d78c84ab6d4e448623bde0a..56971943d2610f887cd85b8e768cb28d6f8223ab 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -824,6 +824,19 @@ extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 	(ehi)->desc_len = 0; \
 } while (0)
 
+static inline void ata_ehi_hotplugged(struct ata_eh_info *ehi)
+{
+	if (ehi->flags & ATA_EHI_HOTPLUGGED)
+		return;
+
+	ehi->flags |= ATA_EHI_HOTPLUGGED;
+	ehi->hotplug_timestamp = jiffies;
+
+	ehi->err_mask |= AC_ERR_ATA_BUS;
+	ehi->action |= ATA_EH_SOFTRESET;
+	ehi->probe_mask |= (1 << ATA_MAX_DEVICES) - 1;
+}
+
 /*
  * qc helpers
  */