diff mbox series

[v3,1/3] scsi: ufs: Fix task management request completion timeout

Message ID 1611807365-35513-2-git-send-email-cang@codeaurora.org (mailing list archive)
State Changes Requested
Headers show
Series Three fixes for task management request implementation | expand

Commit Message

Can Guo Jan. 28, 2021, 4:16 a.m. UTC
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(+)

Comments

Bart Van Assche Jan. 29, 2021, 3:22 a.m. UTC | #1
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.
Can Guo Jan. 29, 2021, 5:46 a.m. UTC | #2
On 2021-01-29 11:22, Bart Van Assche wrote:
> 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?
> 

Block mq driver gives 30s as default timeout,
TMR timeout is 100ms in UFS driver. So we don't
need a timeout handler as of now.

Thanks,
Can Guo.

> Thanks,
> 
> Bart.
diff mbox series

Patch

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);