linux-kernel - Re: [PATCH v2 4/6] clk: qcom: Use HW_CTRL_TRIGGER flag to switch video GDSC to HW mode

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Message-ID: <ef1439f8-4a9b-53b4-34be-1229b39d2310@quicinc.com>
Date:   Mon, 28 Aug 2023 12:18:30 +0530
From:   Jagadeesh Kona <quic_jkona@...cinc.com>
To:     Konrad Dybcio <konrad.dybcio@...aro.org>,
        Abel Vesa <abel.vesa@...aro.org>
CC:     "Rafael J . Wysocki" <rafael@...nel.org>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Bjorn Andersson <andersson@...nel.org>,
        "Andy Gross" <agross@...nel.org>,
        Mike Turquette <mturquette@...libre.com>,
        "Stephen Boyd" <sboyd@...nel.org>,
        Taniya Das <tdas@....qualcomm.com>, <linux-pm@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        <linux-arm-msm@...r.kernel.org>,
        Ajit Pandey <quic_ajipan@...cinc.com>,
        Imran Shaik <quic_imrashai@...cinc.com>
Subject: Re: [PATCH v2 4/6] clk: qcom: Use HW_CTRL_TRIGGER flag to switch
 video GDSC to HW mode



On 8/26/2023 4:17 PM, Konrad Dybcio wrote:
> On 23.08.2023 12:41, Abel Vesa wrote:
>> On 23-08-16 19:56:46, Konrad Dybcio wrote:
>>> On 16.08.2023 16:57, Abel Vesa wrote:
>>>> From: Jagadeesh Kona <quic_jkona@...cinc.com>
>>>>
>>>> The current HW_CTRL flag switches the video GDSC to HW control mode as
>>>> part of GDSC enable itself, instead of that use HW_CTRL_TRIGGER flag to
>>>> give consumer drivers more control and switch the GDSC mode as and when
>>>> required.
>>>>
>>>> HW_CTRL_TRIGGER flag allows consumer drivers to switch the video GDSC to
>>>> HW/SW control modes at runtime using dev_pm_genpd_set_hwmode API.
>>>>
>>>> Signed-off-by: Jagadeesh Kona <quic_jkona@...cinc.com>
>>>> Signed-off-by: Abel Vesa <abel.vesa@...aro.org>
>>>> ---
>>> Do we have any use for the HW_CTRL flag?
>>>
>>> Perhaps it should be renamed to HW_CTRL_ALWAYS?
>>>
>>> Or even better, *if and only if* that is necessary, add a common
>>> property like "always_hw_managed" to the genpd code?
>>
>> The HW_CTRL flag is still needed for the consumers that expect the GDSC
>> to be have the HW control bit set right after it gets enabled.
> Guess the correct question here would be.. Are there any?
> 

Yes, Display GDSC(mdss_gdsc) is required to be controlled always in HW 
control mode when it is enabled.

Thanks,
Jagadeesh

> Konrad