[PATCH 1/2] ufs: Suppress false positive unhandled interrupt messages

[Bart Van Assche <bvanassche@acm.org>]

From ufshcd_transfer_req_compl():
<quote>Resetting interrupt aggregation counters first and reading the
DOOR_BELL afterward allows us to handle all the completed requests.
In order to prevent other interrupts starvation the DB is read once
after reset. The down side of this solution is the possibility of
false interrupt if device completes another request after resetting
aggregation and before reading the DB.</quote>

This patch prevents that ufshcd_intr() reports a false positive
"Unhandled interrupt" message if the above scenario is triggered.

Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Bean Huo <beanhuo@micron.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Suggested-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/ufs/ufshcd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c541b6953863..d330eae02890 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6454,7 +6454,8 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 	}
 
 	if (enabled_intr_status && retval == IRQ_NONE &&
-				!ufshcd_eh_in_progress(hba)) {
+	    (!(enabled_intr_status & UTP_TRANSFER_REQ_COMPL) ||
+	     hba->outstanding_reqs) && !ufshcd_eh_in_progress(hba)) {
 		dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x, 0x%08x)\n",
 					__func__,
 					intr_status,