[PATCH] libata: implement ATA_EHI_RESUME_LINK

Implement ATA_EHI_RESUME_LINK, which indicates that the link needs to
be resumed.  This used to be implied by ATA_EHI_HOTPLUGGED.  However,
hotplug isn't the only event which requires link resume and separating
this out allows other places to request link resume.  This
differentiation also allows better debounce timing selection.

This patch converts user scan to use ATA_EHI_RESUME_LINK.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index ccab1d7..90db054 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2627,13 +2627,14 @@
 	const unsigned long *timing;
 	int rc;
 
-	/* hotplug? */
-	if (ehc->i.flags & ATA_EHI_HOTPLUGGED) {
-		if (ap->flags & ATA_FLAG_HRST_TO_RESUME)
-			ehc->i.action |= ATA_EH_HARDRESET;
-		if (ap->flags & ATA_FLAG_SKIP_D2H_BSY)
-			ata_wait_spinup(ap);
-	}
+	/* handle link resume & hotplug spinup */
+	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
+	    (ap->flags & ATA_FLAG_HRST_TO_RESUME))
+		ehc->i.action |= ATA_EH_HARDRESET;
+
+	if ((ehc->i.flags & ATA_EHI_HOTPLUGGED) &&
+	    (ap->flags & ATA_FLAG_SKIP_D2H_BSY))
+		ata_wait_spinup(ap);
 
 	/* if we're about to do hardreset, nothing more to do */
 	if (ehc->i.action & ATA_EH_HARDRESET)
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 153452e..ba3e515 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -3011,6 +3011,7 @@
 		if (dev) {
 			ap->eh_info.probe_mask |= 1 << dev->devno;
 			ap->eh_info.action |= ATA_EH_SOFTRESET;
+			ap->eh_info.flags |= ATA_EHI_RESUME_LINK;
 		} else
 			rc = -EINVAL;
 	}
diff --git a/include/linux/libata.h b/include/linux/libata.h
index b5d247d..4d4ed2c 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -259,6 +259,7 @@
 
 	/* ata_eh_info->flags */
 	ATA_EHI_HOTPLUGGED	= (1 << 0),  /* could have been hotplugged */
+	ATA_EHI_RESUME_LINK	= (1 << 1),  /* need to resume link */
 
 	ATA_EHI_DID_RESET	= (1 << 16), /* already reset this port */
 
@@ -836,7 +837,7 @@
 	if (ehi->flags & ATA_EHI_HOTPLUGGED)
 		return;
 
-	ehi->flags |= ATA_EHI_HOTPLUGGED;
+	ehi->flags |= ATA_EHI_HOTPLUGGED | ATA_EHI_RESUME_LINK;
 	ehi->hotplug_timestamp = jiffies;
 
 	ehi->err_mask |= AC_ERR_ATA_BUS;