Revert "Move xen patchset to new version's subdir."

[people/pmueller/ipfire-2.x.git] / src / patches / suse-2.6.27.25 / patches.drivers / libata-clear-ering-on-resume

From: Tejun Heo <tj@kernel.org>
Subject: libata: clear ering on resume
References: bnc#486803

Error timestamps are in jiffies which doesn't run while suspended and
PHY events during resume isn't too uncommon.  When the two are
combined, it can lead to unnecessary speed downs if the machine is
suspended and resumed repeatedly.  Clear error history on resume.

This was reported and verified in bnc#486803 by Vladimir Botka.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Vladimir Botka <vbotka@novell.com>
Signed-off-by: Tejun Heo <teheo@suse.de>
---
 drivers/ata/libata-eh.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3158,6 +3158,8 @@ static void ata_eh_handle_port_suspend(s
  */
 static void ata_eh_handle_port_resume(struct ata_port *ap)
 {
+	struct ata_link *link;
+	struct ata_device *dev;
 	unsigned long flags;
 	int rc = 0;
 
@@ -3172,6 +3174,17 @@ static void ata_eh_handle_port_resume(st
 
 	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
 
+	/*
+	 * Error timestamps are in jiffies which doesn't run while
+	 * suspended and PHY events during resume isn't too uncommon.
+	 * When the two are combined, it can lead to unnecessary speed
+	 * downs if the machine is suspended and resumed repeatedly.
+	 * Clear error history.
+	 */
+	ata_port_for_each_link(link, ap)
+		ata_link_for_each_dev(dev, link)
+			ata_ering_clear(&dev->ering);
+
 	ata_acpi_set_state(ap, PMSG_ON);
 
 	if (ap->ops->port_resume)