libata-acpi: implement _GTM/_STM support

Implement _GTM/_STM support.  acpi_gtm is added to ata_port which
stores _GTM parameters over suspend/resume cycle.  A new hook
ata_acpi_on_suspend() is responsible for storing _GTM parameters
during suspend.  _STM is executed in ata_acpi_on_resume().  With this
change, invoking _GTF is safe on IDE hierarchy and acpi_sata check
before _GTF is removed.

ata_acpi_gtm() and ata_acpi_stm() implementation is taken from Alan
Cox's pata_acpi implementation.  ata_acpi_gtm() is fixed such that the
result parameter is not shifted by sizeof(union acpi_object).

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index fed217db82d2..9ee0a8c08d96 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2154,19 +2154,25 @@ static void ata_eh_handle_port_suspend(struct ata_port *ap)
 
         WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
 
+        /* tell ACPI we're suspending */
+        rc = ata_acpi_on_suspend(ap);
+        if (rc)
+                goto out;
+
         /* suspend */
         ata_eh_freeze_port(ap);
 
         if (ap->ops->port_suspend)
                 rc = ap->ops->port_suspend(ap, ap->pm_mesg);
 
+ out:
         /* report result */
         spin_lock_irqsave(ap->lock, flags);
 
         ap->pflags &= ~ATA_PFLAG_PM_PENDING;
         if (rc == 0)
                 ap->pflags |= ATA_PFLAG_SUSPENDED;
-        else
+        else if (ap->pflags & ATA_PFLAG_FROZEN)
                 ata_port_schedule_eh(ap);
 
         if (ap->pm_result) {