Re: [PATCH v4] ufs: core: print UFSHCD capabilities in controller's sysfs node

From: Bart Van Assche
Date: Mon Aug 01 2022 - 13:48:54 EST


On 7/28/22 22:13, Daniil Lunev wrote:
Allows userspace to check if Clock Scaling, Write Booster functionality
status.

The above sentence is not complete. Did you perhaps want to write "are supported by the host controller" instead of "status"?

+What: /sys/bus/platform/drivers/ufshcd/*/capabilities/clock_scaling
+What: /sys/bus/platform/devices/*.ufs/capabilities/clock_scaling
+Date: July 2022
+Contact: Daniil Lunev <dlunev@xxxxxxxxxxxx>
+Description: Indicates status of clock scaling.
+
+ == ============================
+ 0 Clock scaling is not enabled.
+ 1 Clock scaling is enabled.
+ == ============================
+
+ The file is read only.

I don't think the above documentation is correct. My understanding is that the UFSHCD_CAP_CLK_SCALING flag indicates whether or not the host controller supports clock scaling. It does not indicate whether or not clock scaling is enabled.

+What: /sys/bus/platform/drivers/ufshcd/*/capabilities/write_booster
+What: /sys/bus/platform/devices/*.ufs/capabilities/write_booster
+Date: July 2022
+Contact: Daniil Lunev <dlunev@xxxxxxxxxxxx>
+Description: Indicates status of Write Booster.
+
+ == ============================
+ 0 Write Booster can not be enabled.
+ 1 Write Booster can be enabled.
+ == ============================
+
+ The file is read only.

Please change "can not / can be enabled" into "is not supported by the host controller / is supported by the host controller".

Thanks,

Bart.