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

From: Can Guo <quic_cang@quicinc.com>
To: Bart Van Assche <bvanassche@acm.org>, <mani@kernel.org>,
	<quic_nguyenb@quicinc.com>, <quic_nitirawa@quicinc.com>,
	<martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>, Bean Huo <beanhuo@micron.com>,
	Lu Hongfei <luhongfei@vivo.com>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 6/6] scsi: ufs: ufs-sysfs: Introduce UFS power info sysfs nodes
Date: Tue, 31 Oct 2023 12:53:39 +0800	[thread overview]
Message-ID: <c035a67e-d0f2-f235-ea75-36cb31dc7e75@quicinc.com> (raw)
In-Reply-To: <de7e76f8-5ed6-4de0-8084-24e220deb4b3@acm.org>

Hi Bart,

On 9/18/2023 11:36 PM, Bart Van Assche wrote:
> 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.

Sure

>
>> -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?
Yes, my bad, good catch.
>
>> +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@quicinc.com>
>> -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.
Sure
>
>> +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@quicinc.com>
>> +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.
Sure
>
>> +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@quicinc.com>
>> +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.
Sure
>
>> +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@quicinc.com>
>> +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.
Sure
>
>> +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@quicinc.com>
>> +Description:    This file shows the the state of the UFS link.
>
> Please document the meaning of the numbers reported through this sysfs 
> attribute.

Sure

Thanks,

Can Guo.

>
> Thanks,
>
> Bart.