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Date:   Mon, 1 Aug 2022 10:48:45 -0700
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Subject: Re: [PATCH v4] ufs: core: print UFSHCD capabilities in controller's
 sysfs node
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To:     Daniil Lunev <dlunev@chromium.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        Bean Huo <beanhuo@micron.com>, Can Guo <cang@codeaurora.org>,
        Daejun Park <daejun7.park@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        Sohaib Mohamed <sohaib.amhmd@gmail.com>,
        Stanley Chu <stanley.chu@mediatek.com>,
        linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
References: <20220729151301.v4.1.Ibf9efc9be50783eeee55befa2270b7d38552354c@changeid>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20220729151301.v4.1.Ibf9efc9be50783eeee55befa2270b7d38552354c@changeid>
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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@chromium.org>
> +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@chromium.org>
> +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.