scsi: ufs: change msleep to usleep_range (838c1efc) · Commits · 戴 / test

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: ([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>

drivers/scsi/ufs/ufshcd.c

+2 −8

Original line number	Diff line number	Diff line
		@@ -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 */

Admin message