libata: track SLEEP state and issue SRST to wake it up

ATA devices in SLEEP mode don't respond to any commands.  SRST is
necessary to wake it up.  Till now, when a command is issued to a
device in SLEEP mode, the command times out, which makes EH reset the
device and retry the command after that, causing a long delay.

This patch makes libata track SLEEP state and issue SRST automatically
if a command is about to be issued to a device in SLEEP.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Bruce Allen <ballen@gravity.phys.uwm.edu>
Cc: Andrew Paprocki <andrew@ishiboo.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/ata.h b/include/linux/ata.h
index 8263a7b74d34..e21c002c3a4a 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -180,6 +180,7 @@ enum {
         ATA_CMD_VERIFY_EXT      = 0x42,
         ATA_CMD_STANDBYNOW1     = 0xE0,
         ATA_CMD_IDLEIMMEDIATE   = 0xE1,
+        ATA_CMD_SLEEP           = 0xE6,
         ATA_CMD_INIT_DEV_PARAMS = 0x91,
         ATA_CMD_READ_NATIVE_MAX = 0xF8,
         ATA_CMD_READ_NATIVE_MAX_EXT = 0x27,
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6fd24e03622e..2f0fc636b4b6 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -138,6 +138,7 @@ enum {
         ATA_DFLAG_PIO           = (1 << 12), /* device limited to PIO mode */
         ATA_DFLAG_NCQ_OFF       = (1 << 13), /* device limited to non-NCQ mode */
         ATA_DFLAG_SPUNDOWN      = (1 << 14), /* XXX: for spindown_compat */
+        ATA_DFLAG_SLEEPING      = (1 << 15), /* device is sleeping */
         ATA_DFLAG_INIT_MASK     = (1 << 16) - 1,
 
         ATA_DFLAG_DETACH        = (1 << 16),