[PATCH v1] ufs: core: remove dev cmd clock scaling busy

[PATCH v1] ufs: core: remove dev cmd clock scaling busy

[peter.wang]

From: Peter Wang <peter.wang@mediatek.com>

If dev command timeout, clk_scaling.active_reqs is not decrease
and cause clock scaling framework abnormal. But it is complicated to
handle different dev command timeout case in legacy mode or mcq mode.
Besides, dev cmd is rare used and busy time is short.
So remove clock scaling busy window for dev cmd is properly.
Same as uic or tm cmd which doesn't update busy window too.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
---
 drivers/ufs/core/ufshcd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index c2df07545f96..474d5dded7ed 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2165,7 +2165,8 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag,
 	lrbp->compl_time_stamp = ktime_set(0, 0);
 	lrbp->compl_time_stamp_local_clock = 0;
 	ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
-	ufshcd_clk_scaling_start_busy(hba);
+	if (lrbp->cmd)
+		ufshcd_clk_scaling_start_busy(hba);
 	if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
 		ufshcd_start_monitor(hba, lrbp);
 
@@ -5405,7 +5406,6 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag,
 				lrbp->utr_descriptor_ptr->header.ocs = ocs;
 			}
 			complete(hba->dev_cmd.complete);
-			ufshcd_clk_scaling_update_busy(hba);
 		}
 	}
 }
-- 
2.18.0

Re: [PATCH v1] ufs: core: remove dev cmd clock scaling busy

[Stanley Chu]

On Wed, Oct 4, 2023 at 2:25 PM <peter.wang@mediatek.com> wrote:
>
> From: Peter Wang <peter.wang@mediatek.com>
>
> If dev command timeout, clk_scaling.active_reqs is not decrease
> and cause clock scaling framework abnormal. But it is complicated to
> handle different dev command timeout case in legacy mode or mcq mode.
> Besides, dev cmd is rare used and busy time is short.
> So remove clock scaling busy window for dev cmd is properly.
> Same as uic or tm cmd which doesn't update busy window too.
>
> Signed-off-by: Peter Wang <peter.wang@mediatek.com>

It makes sense to me since clock scaling is aimed at balancing
performance and power consumption for different workloads, which
should be data workloads rather than device commands.

Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>

Re: [PATCH v1] ufs: core: remove dev cmd clock scaling busy

[Martin K. Petersen]

Peter,

> If dev command timeout, clk_scaling.active_reqs is not decrease and
> cause clock scaling framework abnormal. But it is complicated to
> handle different dev command timeout case in legacy mode or mcq mode.
> Besides, dev cmd is rare used and busy time is short. So remove clock
> scaling busy window for dev cmd is properly. Same as uic or tm cmd
> which doesn't update busy window too.

Applied to 6.7/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering