Re: [PATCH 6/6] scsi: ufs: ufs-sysfs: Introduce UFS power info sysfs nodes

From: Bart Van Assche
Date: Mon Sep 18 2023 - 11:41:49 EST


On 9/10/23 22:59, Can Guo wrote:
Having UFS power info available in sysfs makes it easier to tell the state
of the link during runtime considering we have a bounch of power saving
features and various combinations for backward compatiblity.

bounch -> bunch
compatiblity -> compatibility

Additionally, please combine this patch with patch 5/6 into a single patch.

-What: /sys/bus/platform/drivers/ufshcd/*/monitor/write_req_latency_sum
-What: /sys/bus/platform/devices/*.ufs/monitor/write_req_latency_sum
-Date: January 2021

Has the above information perhaps been removed by accident?

+What: /sys/bus/platform/drivers/ufshcd/*/power_info/gear
+What: /sys/bus/platform/devices/*.ufs/power_info/gear
+Date: September 2023
Contact: Can Guo <quic_cang@xxxxxxxxxxx>
-Description: This file shows the total latency (in micro seconds) of write
- requests after monitor gets started.
+Description: This file shows the gear of UFS link.
+
+ The file is read only.

Please explain what "gear" means and also what the unit is of the numbers reported via this sysfs attribute.

+What: /sys/bus/platform/drivers/ufshcd/*/power_info/mode
+What: /sys/bus/platform/devices/*.ufs/power_info/mode
+Date: September 2023
+Contact: Can Guo <quic_cang@xxxxxxxxxxx>
+Description: This file shows the power mode of UFS link.
+
+ The file is read only.

Please document the meaning of the numbers reported via this sysfs attribute.

+What: /sys/bus/platform/drivers/ufshcd/*/power_info/rate
+What: /sys/bus/platform/devices/*.ufs/power_info/rate
+Date: September 2023
+Contact: Can Guo <quic_cang@xxxxxxxxxxx>
+Description: This file shows the high speed rate of UFS link.
+
+ The file is read only.

Please document the unit of the numbers reported via this sysfs attribute.

+What: /sys/bus/platform/drivers/ufshcd/*/power_info/dev_pm
+What: /sys/bus/platform/devices/*.ufs/power_info/dev_pm
+Date: September 2023
+Contact: Can Guo <quic_cang@xxxxxxxxxxx>
+Description: This file shows the UFS device power mode, i.e., the power mode
+ set to UFS device via the Start Stop Unit command.

Please document the meaning of the numbers reported through this sysfs attribute.

+What: /sys/bus/platform/drivers/ufshcd/*/power_info/link_state
+What: /sys/bus/platform/devices/*.ufs/power_info/link_state
+Date: September 2023
+Contact: Can Guo <quic_cang@xxxxxxxxxxx>
+Description: This file shows the the state of the UFS link.

Please document the meaning of the numbers reported through this sysfs attribute.

Thanks,

Bart.