src/patches/suse-2.6.27.31/patches.drivers/libata-clear-ering-on-resume

   1 From: Tejun Heo <tj@kernel.org>
   2 Subject: libata: clear ering on resume
   3 References: bnc#486803
   4
   5 Error timestamps are in jiffies which doesn't run while suspended and
   6 PHY events during resume isn't too uncommon.  When the two are
   7 combined, it can lead to unnecessary speed downs if the machine is
   8 suspended and resumed repeatedly.  Clear error history on resume.
   9
  10 This was reported and verified in bnc#486803 by Vladimir Botka.
  11
  12 Signed-off-by: Tejun Heo <tj@kernel.org>
  13 Reported-by: Vladimir Botka <vbotka@novell.com>
  14 Signed-off-by: Tejun Heo <teheo@suse.de>
  15 ---
  16  drivers/ata/libata-eh.c |   13 +++++++++++++
  17  1 file changed, 13 insertions(+)
  18
  19 --- a/drivers/ata/libata-eh.c
  20 +++ b/drivers/ata/libata-eh.c
  21 @@ -3158,6 +3158,8 @@ static void ata_eh_handle_port_suspend(s
  22   */
  23  static void ata_eh_handle_port_resume(struct ata_port *ap)
  24  {
  25 +       struct ata_link *link;
  26 +       struct ata_device *dev;
  27         unsigned long flags;
  28         int rc = 0;
  29
  30 @@ -3172,6 +3174,17 @@ static void ata_eh_handle_port_resume(st
  31
  32         WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
  33
  34 +       /*
  35 +        * Error timestamps are in jiffies which doesn't run while
  36 +        * suspended and PHY events during resume isn't too uncommon.
  37 +        * When the two are combined, it can lead to unnecessary speed
  38 +        * downs if the machine is suspended and resumed repeatedly.
  39 +        * Clear error history.
  40 +        */
  41 +       ata_port_for_each_link(link, ap)
  42 +               ata_link_for_each_dev(dev, link)
  43 +                       ata_ering_clear(&dev->ering);
  44 +
  45         ata_acpi_set_state(ap, PMSG_ON);
  46
  47         if (ap->ops->port_resume)