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Subject: RE:(2) [PATCH] scsi: ufs: Optimize the WB flush process to save
 device power consumption
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Sender: Jinyoung CHOI <j-young.choi@samsung.com>
From:   Jinyoung CHOI <j-young.choi@samsung.com>
To:     Avri Altman <Avri.Altman@wdc.com>, Lu Hongfei <luhongfei@vivo.com>,
        ALIM AKHTAR <alim.akhtar@samsung.com>,
        Bart Van Assche <bvanassche@acm.org>,
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        Asutosh Das <quic_asutoshd@quicinc.com>,
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        Keoseong Park <keosung.park@samsung.com>,
        Arthur Simchaev <Arthur.Simchaev@wdc.com>,
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        Tang Huan <tanghuan@vivo.com>
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Date:   Thu, 29 Jun 2023 12:11:52 +0900
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>> 
>> In the original logic, WB Hibern Flush was always on.
>> During suspend flow, the host will determine whether the device needs
>> BKOP or WB flush, and if so, it will keep VCC supply.
>> WB flush is only a part of BKOP, and device that needs BKOP do not
>> necessarily need WB flush if the conditions are not met. Therefore,
>> if WB flush is not needed, it will be better to disable WB Hibern
>> Flush,..... 
>I beg to differ on this conclusion.
>If you expect SLC write performance, without fluctuations,
>the host should let the device manage its wb buffer on its own.
>This is exactly what flush on hibernate does and better leave it be.
>
>Thanks,
>Avri

Hi, Lu Hongfei.

I agree with avri.
In fact, I am not sure if there will be a significant improvement in
power consumption.
In addition, for the toggle of the function, a code that compares with
the existing value must be added to prevent unnecessary queries.

Best Regards,
Jinyoung.