scsi: ufs: Suppress false positive unhandled interrupt messages

From ufshcd_transfer_req_compl():

    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.

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

Link: https://lore.kernel.org/r/20210519202058.12634-2-bvanassche@acm.org
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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c382260e0cf7e6fdfe90196cfa5753c1f92ab0ef..af527e77fe66aa1b00afece5003f168843f6a714 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6453,7 +6453,8 @@ 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,