[PATCH V1 1/2] mmc: core: Check request type before completing the request

Veerabhadrarao Badiganti
2020-05-06T14:35:08Z

In the request completion path with CQE, request type is being checked
after the request is getting completed. This is resulting in returning
the wrong request type and leading to the IO hang issue.

ASYNC request type is getting returned for DCMD type requests.
Because of this mismatch, mq->cqe_busy flag is never getting cleared
and the driver is not invoking blk_mq_hw_run_queue. So requests are not
getting dispatched to the LLD from the block layer.

All these eventually leading to IO hang issues.
So, get the request type before completing the request.

Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
---
drivers/mmc/core/block.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 8499b56..c5367e2 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1370,6 +1370,7 @@ static void mmc_blk_cqe_complete_rq(struct mmc_queue *mq, struct request *req)
struct mmc_request *mrq = &mqrq->brq.mrq;
struct request_queue *q = req->q;
struct mmc_host *host = mq->card->host;
+ enum mmc_issue_type issue_type = mmc_issue_type(mq, req);
unsigned long flags;
bool put_card;
int err;
@@ -1399,7 +1400,7 @@ static void mmc_blk_cqe_complete_rq(struct mmc_queue *mq, struct request *req)

spin_lock_irqsave(&mq->lock, flags);

- mq->in_flight[mmc_issue_type(mq, req)] -= 1;
+ mq->in_flight[issue_type] -= 1;

put_card = (mmc_tot_in_flight(mq) == 0);

--
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