linux-kernel - Re: [Freedreno] [PATCH v1 1/5] drm/msm/dp: remove pm_runtime_xxx() from dp

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Date:   Sun, 9 Jul 2023 21:00:00 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc:     Kuogee Hsieh <quic_khsieh@...cinc.com>,
        dri-devel@...ts.freedesktop.org, robdclark@...il.com,
        sean@...rly.run, swboyd@...omium.org, dianders@...omium.org,
        vkoul@...nel.org, daniel@...ll.ch, airlied@...il.com,
        agross@...nel.org, andersson@...nel.org, quic_sbillaka@...cinc.com,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        marijn.suijten@...ainline.org, quic_jesszhan@...cinc.com,
        freedreno@...ts.freedesktop.org
Subject: Re: [Freedreno] [PATCH v1 1/5] drm/msm/dp: remove pm_runtime_xxx()
 from dp_power.c

On Sun, 9 Jul 2023 at 20:22, Abhinav Kumar <quic_abhinavk@...cinc.com> wrote:
>
>
>
> On 7/7/2023 5:06 PM, Dmitry Baryshkov wrote:
> > On 08/07/2023 02:52, Kuogee Hsieh wrote:
> >> Since both pm_runtime_resume() and pm_runtime_suspend() are not
> >> populated at dp_pm_ops. Those pm_runtime_get/put() functions within
> >> dp_power.c will not have any effects in addition to increase/decrease
> >> power counter.
> >
> > Lie.
> >
>
> Even if the commit text is incorrect, review comments like this are not
> helping the patch nor the author and will just get ignored anyway.

The review comment might be overreacting, excuse me. I was really
impressed by the commit message, which contradicts the basic source
code. pm_runtime_get() does a lot more than just increasing the power
counter.

> >> Also pm_runtime_xxx() should be executed at top
> >> layer.
> >
> > Why?
> >
>
> I guess he meant to centralize this around dp_display.c. Will elaborate
> while posting the next rev.
>
> >>
> >> Signed-off-by: Kuogee Hsieh <quic_khsieh@...cinc.com>
> >> ---
> >>   drivers/gpu/drm/msm/dp/dp_power.c | 9 ---------
> >>   1 file changed, 9 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/msm/dp/dp_power.c
> >> b/drivers/gpu/drm/msm/dp/dp_power.c
> >> index 5cb84ca..ed2f62a 100644
> >> --- a/drivers/gpu/drm/msm/dp/dp_power.c
> >> +++ b/drivers/gpu/drm/msm/dp/dp_power.c
> >> @@ -152,8 +152,6 @@ int dp_power_client_init(struct dp_power *dp_power)
> >>       power = container_of(dp_power, struct dp_power_private, dp_power);
> >> -    pm_runtime_enable(power->dev);
> >> -
> >>       return dp_power_clk_init(power);
> >>   }
> >> @@ -162,8 +160,6 @@ void dp_power_client_deinit(struct dp_power
> >> *dp_power)
> >>       struct dp_power_private *power;
> >>       power = container_of(dp_power, struct dp_power_private, dp_power);
> >> -
> >> -    pm_runtime_disable(power->dev);
> >>   }
> >>   int dp_power_init(struct dp_power *dp_power)
> >> @@ -173,11 +169,7 @@ int dp_power_init(struct dp_power *dp_power)
> >>       power = container_of(dp_power, struct dp_power_private, dp_power);
> >> -    pm_runtime_get_sync(power->dev);
> >> -
> >>       rc = dp_power_clk_enable(dp_power, DP_CORE_PM, true);
> >> -    if (rc)
> >> -        pm_runtime_put_sync(power->dev);
> >>       return rc;
> >>   }
> >> @@ -189,7 +181,6 @@ int dp_power_deinit(struct dp_power *dp_power)
> >>       power = container_of(dp_power, struct dp_power_private, dp_power);
> >>       dp_power_clk_enable(dp_power, DP_CORE_PM, false);
> >> -    pm_runtime_put_sync(power->dev);
> >>       return 0;
> >>   }
> >



-- 
With best wishes
Dmitry