2021-04-01 07:40:59

by Can Guo

Subject: [PATCH v5 1/2] scsi: ufs: Fix task management request completion timeout

ufshcd_tmc_handler() calls blk_mq_tagset_busy_iter(fn = ufshcd_compl_tm()),
but since blk_mq_tagset_busy_iter() only iterates over all reserved tags
and requests which are not in IDLE state, ufshcd_compl_tm() never gets a
chance to run. Thus, TMR always ends up with completion timeout. Fix it by
calling blk_mq_start_request() in __ufshcd_issue_tm_cmd().

Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs")

Signed-off-by: Can Guo <[email protected]>
---
drivers/scsi/ufs/ufshcd.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index b49555fa..d4f8cb2 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6464,6 +6464,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,

spin_lock_irqsave(host->host_lock, flags);
task_tag = hba->nutrs + free_slot;
+ blk_mq_start_request(req);

treq->req_header.dword_0 |= cpu_to_be32(task_tag);

--
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2021-04-02 00:10:50

by Bart Van Assche

Subject: Re: [PATCH v5 1/2] scsi: ufs: Fix task management request completion timeout

On 4/1/21 12:39 AM, Can Guo wrote:
> ufshcd_tmc_handler() calls blk_mq_tagset_busy_iter(fn = ufshcd_compl_tm()),
> but since blk_mq_tagset_busy_iter() only iterates over all reserved tags
> and requests which are not in IDLE state, ufshcd_compl_tm() never gets a
> chance to run. Thus, TMR always ends up with completion timeout. Fix it by
> calling blk_mq_start_request() in __ufshcd_issue_tm_cmd().

Reviewed-by: Bart Van Assche <[email protected]>