Re: [PATCH v4 7/8] drm/msm/dp: add pm_runtime_force_suspend()/resume()

[Dmitry Baryshkov]

On Wed, 27 Sept 2023 at 23:54, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
>
> After incorporated pm_runtime framework into eDP/DP driver, the

incorporating


> original 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 since
> those function are replaced by dp_pm_runtime_suspend() and
> dp_pm_runtime_resume() through pm runtime framework.
> Therefore add pm framework provides functions,
> pm_runtime_force_suspend()/resume() to complete incorporating pm
> runtime framework into DP driver.
>
> Changes in v4:
> -- 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:
> -- 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@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_display.c | 113 ++----------------------------------
>  1 file changed, 5 insertions(+), 108 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 9158a2c..711d262 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -49,7 +49,6 @@ enum {
>         ST_CONNECTED,
>         ST_DISCONNECT_PENDING,
>         ST_DISPLAY_OFF,
> -       ST_SUSPENDED,
>  };
>
>  enum {
> @@ -560,7 +559,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
>         drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
>                         dp->dp_display.connector_type, state);
>
> -       if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
> +       if (state == ST_DISPLAY_OFF) {
>                 mutex_unlock(&dp->event_mutex);
>                 return 0;
>         }
> @@ -674,7 +673,7 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
>         drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
>                         dp->dp_display.connector_type, state);
>
> -       if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
> +       if (state == ST_DISPLAY_OFF) {
>                 mutex_unlock(&dp->event_mutex);
>                 return 0;
>         }
> @@ -1321,110 +1320,10 @@ static int dp_pm_runtime_resume(struct device *dev)
>         return 0;
>  }
>
> -static int dp_pm_resume(struct device *dev)
> -{
> -       struct platform_device *pdev = to_platform_device(dev);
> -       struct msm_dp *dp_display = platform_get_drvdata(pdev);
> -       struct dp_display_private *dp;
> -       int sink_count = 0;
> -
> -       dp = container_of(dp_display, struct dp_display_private, dp_display);
> -
> -       mutex_lock(&dp->event_mutex);
> -
> -       drm_dbg_dp(dp->drm_dev,
> -               "Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
> -               dp->dp_display.connector_type, dp->core_initialized,
> -               dp->phy_initialized, dp_display->power_on);
> -
> -       /* start from disconnected state */
> -       dp->hpd_state = ST_DISCONNECTED;
> -
> -       /* turn on dp ctrl/phy */
> -       dp_display_host_init(dp);
> -
> -       if (dp_display->is_edp)
> -               dp_catalog_ctrl_hpd_enable(dp->catalog);
> -
> -       if (dp_catalog_link_is_connected(dp->catalog)) {
> -               /*
> -                * set sink to normal operation mode -- D0
> -                * before dpcd read
> -                */
> -               dp_display_host_phy_init(dp);
> -               dp_link_psm_config(dp->link, &dp->panel->link_info, false);
> -               sink_count = drm_dp_read_sink_count(dp->aux);
> -               if (sink_count < 0)
> -                       sink_count = 0;
> -
> -               dp_display_host_phy_exit(dp);
> -       }
> -
> -       dp->link->sink_count = sink_count;
> -       /*
> -        * can not declared display is connected unless
> -        * HDMI cable is plugged in and sink_count of
> -        * dongle become 1
> -        * also only signal audio when disconnected
> -        */
> -       if (dp->link->sink_count) {
> -               dp->dp_display.link_ready = true;
> -       } else {
> -               dp->dp_display.link_ready = false;
> -               dp_display_handle_plugged_change(dp_display, false);
> -       }
> -
> -       drm_dbg_dp(dp->drm_dev,
> -               "After, type=%d sink=%d conn=%d core_init=%d phy_init=%d power=%d\n",
> -               dp->dp_display.connector_type, dp->link->sink_count,
> -               dp->dp_display.link_ready, dp->core_initialized,
> -               dp->phy_initialized, dp_display->power_on);
> -
> -       mutex_unlock(&dp->event_mutex);
> -
> -       return 0;
> -}
> -
> -static int dp_pm_suspend(struct device *dev)
> -{
> -       struct platform_device *pdev = to_platform_device(dev);
> -       struct msm_dp *dp_display = platform_get_drvdata(pdev);
> -       struct dp_display_private *dp;
> -
> -       dp = container_of(dp_display, struct dp_display_private, dp_display);
> -
> -       mutex_lock(&dp->event_mutex);
> -
> -       drm_dbg_dp(dp->drm_dev,
> -               "Before, type=%d core_inited=%d  phy_inited=%d power_on=%d\n",
> -               dp->dp_display.connector_type, dp->core_initialized,
> -               dp->phy_initialized, dp_display->power_on);
> -
> -       /* mainlink enabled */
> -       if (dp_power_clk_status(dp->power, DP_CTRL_PM))
> -               dp_ctrl_off_link_stream(dp->ctrl);
> -
> -       dp_display_host_phy_exit(dp);

I was under the impression that dp_pm_runtime_suspend / _resume
functions perform phy init/exit only in eDP cases. Can we really drop
the main suspend/resume functions?

> -
> -       /* host_init will be called at pm_resume */
> -       dp_display_host_deinit(dp);
> -
> -       dp->hpd_state = ST_SUSPENDED;
> -
> -       drm_dbg_dp(dp->drm_dev,
> -               "After, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
> -               dp->dp_display.connector_type, dp->core_initialized,
> -               dp->phy_initialized, dp_display->power_on);
> -
> -       mutex_unlock(&dp->event_mutex);
> -
> -       return 0;
> -}
> -
>  static const struct dev_pm_ops dp_pm_ops = {
>         SET_RUNTIME_PM_OPS(dp_pm_runtime_suspend, dp_pm_runtime_resume, NULL)
> -       .suspend = dp_pm_suspend,
> -       .resume =  dp_pm_resume,
> +       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +                                pm_runtime_force_resume)
>  };
>
>  static struct platform_driver dp_display_driver = {
> @@ -1658,9 +1557,6 @@ void dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
>
>         dp_display = container_of(dp, struct dp_display_private, dp_display);
>
> -       if (dp->is_edp)
> -               dp_hpd_unplug_handle(dp_display, 0);

Why?

> -
>         mutex_lock(&dp_display->event_mutex);
>
>         state = dp_display->hpd_state;
> @@ -1748,6 +1644,7 @@ void dp_bridge_hpd_disable(struct drm_bridge *bridge)
>         dp_catalog_ctrl_hpd_disable(dp->catalog);
>
>         dp_display->internal_hpd = false;
> +       dp->hpd_state = ST_DISCONNECTED;

Why? We have only disabled sending of the HPD events. The dongle might
still be connected.

>
>         pm_runtime_mark_last_busy(&dp->pdev->dev);
>         pm_runtime_put_autosuspend(&dp->pdev->dev);
> --
> 2.7.4
>


--
With best wishes

Dmitry