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Message-ID: <c7e8d791-c8d5-440c-804d-4aa29be40f13@linaro.org>
Date:   Thu, 12 Oct 2023 04:04:07 +0300
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Subject: Re: [PATCH v7 5/7] drm/msm/dp: incorporate pm_runtime framework into
 DP driver
Content-Language: en-GB
To:     Kuogee Hsieh <quic_khsieh@quicinc.com>,
        dri-devel@lists.freedesktop.org, robdclark@gmail.com,
        sean@poorly.run, swboyd@chromium.org, dianders@chromium.org,
        vkoul@kernel.org, daniel@ffwll.ch, airlied@gmail.com,
        agross@kernel.org, andersson@kernel.org
Cc:     quic_abhinavk@quicinc.com, quic_jesszhan@quicinc.com,
        quic_sbillaka@quicinc.com, marijn.suijten@somainline.org,
        freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <1696632910-21942-1-git-send-email-quic_khsieh@quicinc.com>
 <1696632910-21942-6-git-send-email-quic_khsieh@quicinc.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <1696632910-21942-6-git-send-email-quic_khsieh@quicinc.com>
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Precedence: bulk

On 07/10/2023 01:55, Kuogee Hsieh wrote:
> Currently DP driver is executed independent of PM runtime framework.
> This leads msm eDP panel can not being detected by edp_panel driver
> during generic_edp_panel_probe() due to AUX DPCD read failed at
> edp panel driver. Incorporate PM runtime framework into DP driver so
> that host controller's power and clocks are enable/disable through
> PM runtime mechanism.  Once PM runtime framework is incorporated into
> DP driver, waking up device from power up path is not necessary. Hence
> remove it.
> 
> After incorporating pm_runtime framework into eDP/DP driver,
> dp_pm_suspend() to handle power off both DP phy and controller during
> suspend and dp_pm_resume() to handle power on both DP phy and controller
> during resume are not necessary. Therefore both dp_pm_suspend() and
> dp_pm_resume() are dropped and replace with dp_pm_runtime_suspend() and
> dp_pm_runtime_resume() respectively.
> 
> Changes in v7:
> -- add comments to dp_pm_runtime_resume()
> -- add comments to dp_bridge_hpd_enable()
> -- delete dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_notify()
> 
> Changes in v6:
> -- delete dp_power_client_deinit(dp->power);
> -- remove if (!dp->dp_display.is_edp) condition checkout at plug_handle()
> -- remove if (!dp->dp_display.is_edp) condition checkout at unplug_handle()
> -- add IRQF_NO_AUTOEN to devm_request_irq()
> -- add enable_irq() and disable_irq() to pm_runtime_resume()/suspend()
> -- del dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_disable()
> 
> Changes in v5:
> -- remove pm_runtime_put_autosuspend feature, use pm_runtime_put_sync()
> -- squash add pm_runtime_force_suspend()/resume() patch into this patch
> 
> Changes in v4:
> -- reworded commit text to explain why pm_framework is required for
>     edp panel
> -- reworded commit text to explain autosuspend is choiced
> -- delete EV_POWER_PM_GET and PM_EV_POWER_PUT from changes #3
> -- delete dp_display_pm_get() and dp_display_pm_Put() from changes #3
> -- return value from pm_runtime_resume_and_get() directly
> -- check return value of devm_pm_runtime_enable()
> -- delete pm_runtime_xxx from dp_display_remove()
> -- drop dp_display_host_init() from EV_HPD_INIT_SETUP
> -- drop both dp_pm_prepare() and dp_pm_compete() from this change
> -- delete ST_SUSPENDED state
> -- rewording commit text to add more details regrading the purpose
>     of this change
> 
> Changes in v3:
> -- incorporate removing pm_runtime_xx() from dp_pwer.c to this patch
> -- use pm_runtime_resume_and_get() instead of pm_runtime_get()
> -- error checking pm_runtime_resume_and_get() return value
> -- add EV_POWER_PM_GET and PM_EV_POWER_PUT to handle HPD_GPIO case
> -- replace dp_pm_suspend() with pm_runtime_force_suspend()
> -- replace dp_pm_resume() with pm_runtime_force_resume()
> 
> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
>   drivers/gpu/drm/msm/dp/dp_aux.c     |   5 +
>   drivers/gpu/drm/msm/dp/dp_display.c | 177 ++++++++++++++----------------------
>   drivers/gpu/drm/msm/dp/dp_power.c   |  16 ----
>   drivers/gpu/drm/msm/dp/dp_power.h   |  11 ---
>   4 files changed, 72 insertions(+), 137 deletions(-)


[skipped the rest]

> @@ -173,11 +162,7 @@ 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;

Also this can not be as simple as:

int dp_power_init(struct dp_power *dp_power)
{
   	return dp_power_clk_enable(dp_power, DP_CORE_PM, true);
}


>   }-- 
With best wishes
Dmitry