Commit 29707fab authored by Kiwoong Kim's avatar Kiwoong Kim Committed by Martin K. Petersen
Browse files

scsi: ufs: Change fDeviceInit busy wait 

Currently, the UFS driver busy waits for fDeviceInit to be cleared. Provide
an upper bound and sleep between attempts instead of busy waiting.

Link: https://lore.kernel.org/r/1597053747-75171-1-git-send-email-kwmad.kim@samsung.com


Tested-by: default avatarKiwoong Kim <kwmad.kim@samsung.com>
Reviewed-by: default avatarAvri Altman <avri.altman@wdc.com>
Signed-off-by: default avatarKiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent b0008625

drivers/scsi/ufs/ufshcd.c

+21 −12
Original line number Diff line number Diff line
@@ -74,6 +74,9 @@ 
/* Default value of wait time before gating device ref clock */

#define UFSHCD_REF_CLK_GATING_WAIT_US 0xFF /* microsecs */



/* Polling time to wait for fDeviceInit */

#define FDEVICEINIT_COMPL_TIMEOUT 1500 /* millisecs */



#define ufshcd_toggle_vreg(_dev, _vreg, _on)				\

	({                                                              \

		int _ret;                                               \
@@ -4175,9 +4178,9 @@ EXPORT_SYMBOL_GPL(ufshcd_config_pwr_mode); 
 */

static int ufshcd_complete_dev_init(struct ufs_hba *hba)

{

	int i;

	int err;

	bool flag_res = true;

	ktime_t timeout;



	err = ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_SET_FLAG,

		QUERY_FLAG_IDN_FDEVICEINIT, 0, NULL);
@@ -4188,20 +4191,26 @@ static int ufshcd_complete_dev_init(struct ufs_hba *hba) 
		goto out;

	}



	/* poll for max. 1000 iterations for fDeviceInit flag to clear */

	for (i = 0; i < 1000 && !err && flag_res; i++)

		err = ufshcd_query_flag_retry(hba, UPIU_QUERY_OPCODE_READ_FLAG,

	/* Poll fDeviceInit flag to be cleared */

	timeout = ktime_add_ms(ktime_get(), FDEVICEINIT_COMPL_TIMEOUT);

	do {

		err = ufshcd_query_flag(hba, UPIU_QUERY_OPCODE_READ_FLAG,

					QUERY_FLAG_IDN_FDEVICEINIT, 0, &flag_res);

		if (!flag_res)

			break;

		usleep_range(5000, 10000);

	} while (ktime_before(ktime_get(), timeout));



	if (err)

	if (err) {

		dev_err(hba->dev,

				"%s reading fDeviceInit flag failed with error %d\n",

				__func__, err);

	else if (flag_res)

	} else if (flag_res) {

		dev_err(hba->dev,

				"%s fDeviceInit was not cleared by the device\n",

				__func__);



		err = -EBUSY;

	}

out:

	return err;

}