From: Bean Huo <beanhuo@micron.com>
Date: Mon, 15 Jul 2019 11:21:10 +0000
Subject: scsi: ufs: change msleep to usleep_range
Git-commit: 838c1efc6a0adbf44d16e4714f43443db598cdb5
Patch-mainline: v5.4-rc1
References: bsc#1171622
This patch is to change msleep() to usleep_range() based on
Documentation/timers/timers-howto.txt. It suggests using usleep_range()
for small msec(1ms - 20ms) since msleep() will often sleep longer than
desired value.
After changing, booting time will be 5ms-10ms faster than before. I
tested this change on two different platforms, one has 5ms faster, another
one is about 10ms. I think this is different on different platform.
Actually, from UFS host side, 1ms-5ms delay is already sufficient for its
initialization of the local UIC layer.
Fixes: 7a3e97b0dc4b ([SCSI] ufshcd: UFS Host controller driver)
Signed-off-by: Bean Huo <beanhuo@micron.com>
Acked-by: Stanley Chu <stanley.chu@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
drivers/scsi/ufs/ufshcd.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3804a704e565..a383d0f54f5d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -4226,12 +4226,6 @@ static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
{
int retry;
- /*
- * msleep of 1 and 5 used in this function might result in msleep(20),
- * but it was necessary to send the UFS FPGA to reset mode during
- * development and testing of this driver. msleep can be changed to
- * mdelay and retry count can be reduced based on the controller.
- */
if (!ufshcd_is_hba_active(hba))
/* change controller state to "reset state" */
ufshcd_hba_stop(hba, true);
@@ -4254,7 +4248,7 @@ static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
* instruction might be read back.
* This delay can be changed based on the controller.
*/
- msleep(1);
+ usleep_range(1000, 1100);
/* wait for the host controller to complete initialization */
retry = 10;
@@ -4266,7 +4260,7 @@ static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
"Controller enable failed\n");
return -EIO;
}
- msleep(5);
+ usleep_range(5000, 5100);
}
/* enable UIC related interrupts */