[PATCH AUTOSEL 4.9 6/8] scsi: ufs: Improve interrupt handling for shared interrupts

[Sasha Levin <sashal@kernel.org>]

From: Adrian Hunter <adrian.hunter@intel.com>

[ Upstream commit 127d5f7c4b653b8be5eb3b2c7bbe13728f9003ff ]

For shared interrupts, the interrupt status might be zero, so check that
first.

Link: https://lore.kernel.org/r/20200811133936.19171-2-adrian.hunter@intel.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/ufs/ufshcd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1eee82b18be4e..b0841a3fab522 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4398,7 +4398,7 @@ static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
  */
 static irqreturn_t ufshcd_intr(int irq, void *__hba)
 {
-	u32 intr_status, enabled_intr_status;
+	u32 intr_status, enabled_intr_status = 0;
 	irqreturn_t retval = IRQ_NONE;
 	struct ufs_hba *hba = __hba;
 	int retries = hba->nutrs;
@@ -4412,7 +4412,7 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 	 * read, make sure we handle them by checking the interrupt status
 	 * again in a loop until we process all of the reqs before returning.
 	 */
-	do {
+	while (intr_status && retries--) {
 		enabled_intr_status =
 			intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
 		if (intr_status)
@@ -4423,7 +4423,7 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 		}
 
 		intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
-	} while (intr_status && --retries);
+	}
 
 	spin_unlock(hba->host->host_lock);
 	return retval;
-- 
2.25.1