[PATCH] libata: make WARN_ON conditions in ata_sff_hsm_move() more strict

[Tejun Heo <htejun@gmail.com>]

WARN_ON()'s in ata_hsm_move() was too liberal and got triggerred when
it shouldn't (e.g. hotplug events at the right moment).  As the HSM
only deals with device errors and state machine violations, make it
check only against them.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Mark Lord <liml@rtr.ca>
Cc: Albert Lee <albertcc@tw.ibm.com>
---
 drivers/ata/libata-sff.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 1549952..2ec65a8 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -1208,7 +1208,7 @@ fsm_start:
 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
 			ap->print_id, qc->dev->devno, status);
 
-		WARN_ON(qc->err_mask);
+		WARN_ON(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM));
 
 		ap->hsm_task_state = HSM_ST_IDLE;
 
@@ -1222,7 +1222,7 @@ fsm_start:
 		/* make sure qc->err_mask is available to
 		 * know what's wrong and recover
 		 */
-		WARN_ON(qc->err_mask == 0);
+		WARN_ON(!(qc->err_mask & (AC_ERR_DEV | AC_ERR_HSM)));
 
 		ap->hsm_task_state = HSM_ST_IDLE;