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authorYaniv Gardi2016-02-01 15:02:42 +0200
committerMartin K. Petersen2016-02-23 21:27:02 -0500
commitf05ac2e5930506c980817a59a47f903e25f91429 (patch)
treef78b05aa4cb1e15ae77391876c59bb1967104bca
parente5ad406cecc3a13bd1e6242d3e24aaeae32ff972 (diff)
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. Reviewed-by: Gilad Broner <gbroner@codeaurora.org> Reviewed-by: Dolev Raviv <draviv@codeaurora.org> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org> Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/ufs/ufshcd.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e74c53aebf82..e374b79a5b98 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3144,7 +3144,20 @@ 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: