[PATCH] scsi: ufs: Increase fDeviceInit poll frequency

[PATCH] scsi: ufs: Increase fDeviceInit poll frequency

[Bart Van Assche]

From: Konstantin Vyshetsky <vkon@google.com>

UFS devices are expected to clear fDeviceInit flag in single digit
milliseconds. Current values of 5 to 10 millisecond sleep add to
increased latency during the initialization and resume path. This CL
lowers the sleep range to 500 to 1000 microseconds.

Signed-off-by: Konstantin Vyshetsky <vkon@google.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/ufs/ufshcd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3f9caafa91bf..ba9c7f9ec424 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4438,7 +4438,7 @@ static int ufshcd_complete_dev_init(struct ufs_hba *hba)
 					QUERY_FLAG_IDN_FDEVICEINIT, 0, &flag_res);
 		if (!flag_res)
 			break;
-		usleep_range(5000, 10000);
+		usleep_range(500, 1000);
 	} while (ktime_before(ktime_get(), timeout));
 
 	if (err) {

RE: [PATCH] scsi: ufs: Increase fDeviceInit poll frequency

[Avri Altman]

> From: Konstantin Vyshetsky <vkon@google.com>
> 
> UFS devices are expected to clear fDeviceInit flag in single digit milliseconds.
> Current values of 5 to 10 millisecond sleep add to increased latency during
> the initialization and resume path. This CL lowers the sleep range to 500 to
> 1000 microseconds.
> 
> Signed-off-by: Konstantin Vyshetsky <vkon@google.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Avri Altman <avri.altman@wdc.com>

Re: [PATCH] scsi: ufs: Increase fDeviceInit poll frequency

[Martin K. Petersen]

Bart,

> UFS devices are expected to clear fDeviceInit flag in single digit
> milliseconds. Current values of 5 to 10 millisecond sleep add to
> increased latency during the initialization and resume path. This CL
> lowers the sleep range to 500 to 1000 microseconds.

Applied to 5.19/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: ufs: Increase fDeviceInit poll frequency

[Martin K. Petersen]

On Wed, 20 Apr 2022 17:24:29 -0700, Bart Van Assche wrote:

> From: Konstantin Vyshetsky <vkon@google.com>
> 
> UFS devices are expected to clear fDeviceInit flag in single digit
> milliseconds. Current values of 5 to 10 millisecond sleep add to
> increased latency during the initialization and resume path. This CL
> lowers the sleep range to 500 to 1000 microseconds.
> 
> [...]

Applied to 5.19/scsi-queue, thanks!

[1/1] scsi: ufs: Increase fDeviceInit poll frequency
      https://git.kernel.org/mkp/scsi/c/a4e6496fca3f

-- 
Martin K. Petersen	Oracle Linux Engineering