libata: improve EH internal command timeout handling

ATA_TMOUT_INTERNAL which was 30secs were used for all internal
commands which is way too long when something goes wrong.  This patch
implements command type based stepped timeouts.  Different command
types can use different timeouts and each command type can use
different timeout values after timeouts.

ie. the initial timeout is set to a value which should cover most of
the cases but not too long so that run away cases don't delay things
too much.  After the first try times out, the second try can use
longer timeout and if that one times out too, it can go for full 30sec
timeout.

IDENTIFYs use 5s - 10s - 30s timeout and all other commands use 5s -
10s timeouts.

This patch significantly cuts down the needed time to handle failure
cases while still allowing libata to work with nut job devices through
retries.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 1cf803adbc95..f6f9c28ec7f8 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -151,6 +151,8 @@ extern void ata_scsi_dev_rescan(struct work_struct *work);
 extern int ata_bus_probe(struct ata_port *ap);
 
 /* libata-eh.c */
+extern unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd);
+extern void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd);
 extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
 extern void ata_scsi_error(struct Scsi_Host *host);
 extern void ata_port_wait_eh(struct ata_port *ap);