scsi: ufs: Suppress false positive unhandled interrupt messages
authorBart Van Assche <bvanassche@acm.org>
Wed, 19 May 2021 20:20:57 +0000 (13:20 -0700)
committerMartin K. Petersen <martin.petersen@oracle.com>
Tue, 1 Jun 2021 02:48:20 +0000 (22:48 -0400)
commit40d2fd05ecc2b63d1bd8f6686f09941afe85edfe
tree54afa469524b8f2f999d98d0971a69c2447615f3
parenta0815c45c89f544861eae55d85ccee6b1b1451e8
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>
drivers/scsi/ufs/ufshcd.c