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Subject: Re: [PATCH v3 1/3] scsi: ufs: Fix task management request completion
 timeout
To:     Can Guo <cang@codeaurora.org>, jaegeuk@kernel.org,
        asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, linux-scsi@vger.kernel.org,
        kernel-team@android.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        Bean Huo <beanhuo@micron.com>,
        open list <linux-kernel@vger.kernel.org>
References: <1611807365-35513-1-git-send-email-cang@codeaurora.org>
 <1611807365-35513-2-git-send-email-cang@codeaurora.org>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <b73ad496-1658-d587-146a-138ac8f522a9@acm.org>
Date:   Thu, 28 Jan 2021 19:22:45 -0800
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Precedence: bulk

On 1/27/21 8:16 PM, 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().
> 
> Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs")
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
>  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 8da75e6..c0c5925 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6395,6 +6395,7 @@ 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);

blk_mq_start_request() not only marks a request as in-flight but also
starts a timer. However, no timeout handler has been defined in
ufshcd_tmf_ops. Should a timeout handler be defined in that data structure?

Thanks,

Bart.