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Message-ID: <5e7c5c75-cb5f-4afe-9d57-b0cab01a6f26@acm.org>
Date:   Tue, 5 Dec 2023 07:11:56 -1000
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Subject: Re: [PATCH V2 1/3] ufs: core: Add CPU latency QoS support for ufs
 driver
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To:     Naresh Maramaina <quic_mnaresh@quicinc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Peter Wang <peter.wang@mediatek.com>,
        Manivannan Sadhasivam <mani@kernel.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>, chu.stanley@gmail.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
        linux-arm-msm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, quic_cang@quicinc.com,
        quic_nguyenb@quicinc.com, Nitin Rawat <quic_nitirawa@quicinc.com>
References: <20231204143101.64163-1-quic_mnaresh@quicinc.com>
 <20231204143101.64163-2-quic_mnaresh@quicinc.com>
 <590ade27-b4da-49be-933b-e9959aa0cd4c@acm.org>
 <692cd503-5b14-4be6-831d-d8e9c282a95e@quicinc.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <692cd503-5b14-4be6-831d-d8e9c282a95e@quicinc.com>
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On 12/4/23 21:58, Naresh Maramaina wrote:
> On 12/5/2023 12:30 AM, Bart Van Assche wrote:
>> On 12/4/23 06:30, Maramaina Naresh wrote:
>>> +    /* This capability allows the host controller driver to use the 
>>> PM QoS
>>> +     * feature.
>>> +     */
>>> +    UFSHCD_CAP_PM_QOS                = 1 << 13,
>>>   };
>>
>> Why does it depend on the host driver whether or not PM QoS is
>> enabled? Why isn't it enabled unconditionally?
> 
> For some platform vendors power KPI might be more important than random 
> io KPI. Hence this flag is disabled by default and can be enabled based 
> on platform requirement.

How about leaving this flag out unless if a host vendor asks explicitly
for this flag?
>>
>>> + * @pm_qos_req: PM QoS request handle
>>> + * @pm_qos_init: flag to check if pm qos init completed
>>>    */
>>
>> Documentation for pm_qos_init is missing.
>>
> Sorry, i didn't get your comment, i have already added documentation for 
> @pm_qos_init, @pm_qos_req variable as above. Do you want me to add this 
> information some where else as well?

Oops, I meant 'qos_vote'.

Thanks,

Bart.