Commit c4da5b5d authored Jul 24, 2024 by Vamshi Gajjela Committed by Greg Kroah-Hartman Aug 19, 2024

scsi: ufs: core: Fix hba->last_dme_cmd_tstamp timestamp updating logic



commit ab9fd06cb8f0db0854291833fc40c789e43a361f upstream.

The ufshcd_add_delay_before_dme_cmd() always introduces a delay of
MIN_DELAY_BEFORE_DME_CMDS_US between DME commands even when it's not
required. The delay is added when the UFS host controller supplies the
quirk UFSHCD_QUIRK_DELAY_BEFORE_DME_CMDS.

Fix the logic to update hba->last_dme_cmd_tstamp to ensure subsequent DME
commands have the correct delay in the range of 0 to
MIN_DELAY_BEFORE_DME_CMDS_US.

Update the timestamp at the end of the function to ensure it captures the
latest time after any necessary delay has been applied.

Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com>
Link: https://lore.kernel.org/r/20240724135126.1786126-1-vamshigajjela@google.com


Fixes: cad2e03d ("ufs: add support to allow non standard behaviours (quirks)")
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ba15815d

drivers/scsi/ufs/ufshcd.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -3592,13 +3592,18 @@ static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba)
		min_sleep_time_us =
		MIN_DELAY_BEFORE_DME_CMDS_US - delta;
		else
		return; /* no more delay required */
		min_sleep_time_us = 0; /* no more delay required */
		}

		if (min_sleep_time_us > 0) {
		/* allow sleep for extra 50us if needed */
		usleep_range(min_sleep_time_us, min_sleep_time_us + 50);
		}

		/* update the last_dme_cmd_tstamp */
		hba->last_dme_cmd_tstamp = ktime_get();
		}

		/**
		* ufshcd_dme_set_attr - UIC command for DME_SET, DME_PEER_SET
		* @hba: per adapter instance