2020-08-03 09:06:42

by Can Guo

Subject: [PATCH v9 9/9] scsi: ufs: Properly release resources if a task is aborted successfully

In current UFS task abort hook, namely ufshcd_abort(), if a task is
aborted successfully, clock scaling busy time statistics is not updated
and, most important, clk_gating.active_reqs is not decreased, which makes
clk_gating.active_reqs stay above zero forever, thus clock gating would
never happen. To fix it, instead of releasing resources "mannually", use
the existing func __ufshcd_transfer_req_compl(). This can also eliminate
racing of scsi_dma_unmap() from the real completion in IRQ handler path.

Signed-off-by: Can Guo <[email protected]>
CC: Stanley Chu <[email protected]>
---
drivers/scsi/ufs/ufshcd.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index d7d2758..9a48389 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6635,11 +6635,8 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
goto out;
}

- scsi_dma_unmap(cmd);
-
spin_lock_irqsave(host->host_lock, flags);
- ufshcd_outstanding_req_clear(hba, tag);
- hba->lrb[tag].cmd = NULL;
+ __ufshcd_transfer_req_compl(hba, (1UL << tag));
spin_unlock_irqrestore(host->host_lock, flags);

out:
--
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2020-08-03 09:47:12

by Stanley Chu

Subject: Re: [PATCH v9 9/9] scsi: ufs: Properly release resources if a task is aborted successfully

On Mon, 2020-08-03 at 02:04 -0700, Can Guo wrote:
> In current UFS task abort hook, namely ufshcd_abort(), if a task is
> aborted successfully, clock scaling busy time statistics is not updated
> and, most important, clk_gating.active_reqs is not decreased, which makes
> clk_gating.active_reqs stay above zero forever, thus clock gating would
> never happen. To fix it, instead of releasing resources "mannually", use
> the existing func __ufshcd_transfer_req_compl(). This can also eliminate
> racing of scsi_dma_unmap() from the real completion in IRQ handler path.
>
> Signed-off-by: Can Guo <[email protected]>
> CC: Stanley Chu <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index d7d2758..9a48389 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6635,11 +6635,8 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
> goto out;
> }
>
> - scsi_dma_unmap(cmd);
> -
> spin_lock_irqsave(host->host_lock, flags);
> - ufshcd_outstanding_req_clear(hba, tag);
> - hba->lrb[tag].cmd = NULL;
> + __ufshcd_transfer_req_compl(hba, (1UL << tag));
> spin_unlock_irqrestore(host->host_lock, flags);
>
> out:

Reviewed-by: Stanley Chu <[email protected]>