scsi: ufs: avoid exception event handler racing with PM callbacks

If device raises the exception event in the response to the commands
sent during the runtime/system PM callbacks, exception event handler
might run in parallel with PM callbacks and may see unclocked register
accesses. This change fixes this issue by not scheduling the exception
event handler while PM callbacks are running.

Change-Id: I8644f50366d5c87ba6a5048e48703b3723ab241b
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
This commit is contained in:
Subhash Jadavani 2014-12-04 14:17:32 -08:00 committed by David Keitel
parent 4229a8a3ed
commit 60455e93d1

View file

@ -4592,7 +4592,20 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
scsi_status = result & MASK_SCSI_STATUS;
result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
if (ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
/*
* Currently we are only supporting BKOPs exception
* events hence we can ignore BKOPs exception event
* during power management callbacks. BKOPs exception
* event is not expected to be raised in runtime suspend
* callback as it allows the urgent bkops.
* During system suspend, we are anyway forcefully
* disabling the bkops and if urgent bkops is needed
* it will be enabled on system resume. Long term
* solution could be to abort the system suspend if
* UFS device needs urgent BKOPs.
*/
if (!hba->pm_op_in_progress &&
ufshcd_is_exception_event(lrbp->ucd_rsp_ptr))
schedule_work(&hba->eeh_work);
break;
case UPIU_TRANSACTION_REJECT_UPIU: