Re: [PATCH v4 5/8] drm/msm/dp: incorporate pm_runtime framework into DP driver

[Kuogee Hsieh]

On 9/27/2023 2:41 PM, Dmitry Baryshkov wrote:
> On Wed, 27 Sept 2023 at 23:54, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
> > Currently DP driver is executed independent of PM runtime framework.
> > This lead to msm edp panel can not be detected by edp_panel driver at
> > generic_edp_panel_probe() due to aux dpcd read failed at msm edp driver.
> eDP, AUX, DPCD. leads. not being detected, s/at/during.
>
> Also there is no msm eDP driver.
>
> > Incorporating pm runtime framework into DP driver so that both power and
> Incorporate. PM
>
> > clocks to enable/disable host controller fits with PM runtime mechanism.
> Ugh?
>
> > Once pm runtime framework is incorporated into DP driver, wake up device
> waking
>
> > from power up path is not necessary. Hence remove it.
> > Since DP is part of user interface, we choice to use autosuspend feature
> > with timer of one second. pm runtime suspends is prevented from happening
> > until timer expired.
> No, this is not the right reason to use autosuspend. Please use normal
> suspend unless there is a performance regression caused by the
> suspend/resume paths.
>
> > 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
> >
> > 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
> >
> > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/dp/dp_aux.c     |  6 +++
> >   drivers/gpu/drm/msm/dp/dp_display.c | 95 +++++++++++++++++++++++++++----------
> >   drivers/gpu/drm/msm/dp/dp_power.c   | 16 -------
> >   drivers/gpu/drm/msm/dp/dp_power.h   | 11 -----
> >   4 files changed, 77 insertions(+), 51 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
> > index 8e3b677..22eb774 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_aux.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_aux.c
> > @@ -291,6 +291,10 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
> >                  return -EINVAL;
> >          }
> >
> > +       ret = pm_runtime_resume_and_get(dp_aux->dev);
> > +       if (ret)
> > +               return  ret;
> > +
> >          mutex_lock(&aux->mutex);
> >          if (!aux->initted) {
> >                  ret = -EIO;
> > @@ -364,6 +368,8 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
> >
> >   exit:
> >          mutex_unlock(&aux->mutex);
> > +       pm_runtime_mark_last_busy(dp_aux->dev);
> > +       pm_runtime_put_autosuspend(dp_aux->dev);
> >
> >          return ret;
> >   }
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index 3ef141c..bfb4692 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -276,8 +276,6 @@ static int dp_display_bind(struct device *dev, struct device *master,
> >          dp->dp_display.drm_dev = drm;
> >          priv->dp[dp->id] = &dp->dp_display;
> >
> > -
> > -
> Is this also a part of pm_runtime support? No, it is not.
>
> >          dp->drm_dev = drm;
> >          dp->aux->drm_dev = drm;
> >          rc = dp_aux_register(dp->aux);
> > @@ -286,7 +284,6 @@ static int dp_display_bind(struct device *dev, struct device *master,
> >                  goto end;
> >          }
> >
> > -
> And this. If you want to clean up stray empty lines, please split that
> to a separate patch.
>
> >          rc = dp_register_audio_driver(dev, dp->audio);
> >          if (rc) {
> >                  DRM_ERROR("Audio registration Dp failed\n");
> > @@ -310,15 +307,10 @@ static void dp_display_unbind(struct device *dev, struct device *master,
> >          struct dp_display_private *dp = dev_get_dp_display_private(dev);
> >          struct msm_drm_private *priv = dev_get_drvdata(master);
> >
> > -       /* disable all HPD interrupts */
> > -       if (dp->core_initialized)
> > -               dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, false);
> > -
> >          kthread_stop(dp->ev_tsk);
> >
> >          of_dp_aux_depopulate_bus(dp->aux);
> >
> > -       dp_power_client_deinit(dp->power);
> >          dp_unregister_audio_driver(dev, dp->audio);
> >          dp_aux_unregister(dp->aux);
> >          dp->drm_dev = NULL;
> > @@ -460,6 +452,16 @@ static void dp_display_host_deinit(struct dp_display_private *dp)
> >   static int dp_display_usbpd_configure_cb(struct device *dev)
> >   {
> >          struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > +       int ret;
> > +
> > +       if (!dp->dp_display.internal_hpd) {
> I'd say, drop the condition here.
>
> > +               /* hpd through gpio */
> Why? !internal_hpd means any possible way of delivering an HPD event.
> For example, via the USB-C TCPM.
>
> > +               ret = pm_runtime_resume_and_get(&dp->pdev->dev);
> Which function contains corresponding pm_runtime_put()?
>
> > +               if (ret) {
> > +                       DRM_ERROR("failed to start power\n");
> failed to resume
>
> > +                       return ret;
> > +               }
> > +       }
> >
> >          dp_display_host_phy_init(dp);
> >
> > @@ -1086,7 +1088,6 @@ static int hpd_event_thread(void *data)
> >
> >                  switch (todo->event_id) {
> >                  case EV_HPD_INIT_SETUP:
> > -                       dp_display_host_init(dp_priv);
> >                          break;
> >                  case EV_HPD_PLUG_INT:
> >                          dp_hpd_plug_handle(dp_priv, todo->data);
> > @@ -1263,6 +1264,13 @@ static int dp_display_probe(struct platform_device *pdev)
> >
> >          platform_set_drvdata(pdev, &dp->dp_display);
> >
> > +       rc = devm_pm_runtime_enable(&pdev->dev);
> > +       if (rc)
> > +               return rc;
> Missing submodules deinit.
>
> > +
> > +       pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
> > +       pm_runtime_use_autosuspend(&pdev->dev);
> > +
> >          rc = dp_display_request_irq(dp);
> >          if (rc)
> >                  return rc;
> > @@ -1285,6 +1293,34 @@ static int dp_display_remove(struct platform_device *pdev)
> >
> >          platform_set_drvdata(pdev, NULL);
> >
> > +       dp_display_deinit_sub_modules(dp);
> There is already a call to dp_display_deinit_sub_modules() in
> dp_display_remove().
> > +
> > +       return 0;
> > +}
> > +
> > +static int dp_pm_runtime_suspend(struct device *dev)
> > +{
> > +       struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > +
> > +       if (dp->dp_display.is_edp) {
> > +               dp_display_host_phy_exit(dp);
> > +               dp_catalog_ctrl_hpd_disable(dp->catalog);
> > +       }
> I don't see where this code was removed.

this code block is adapted from dp_pm_suspend().

dp_pm_suspend() will be removed at "add 
pm_runtime_force_suspend()/resume()" patch.

> > +       dp_display_host_deinit(dp);
> > +
> > +       return 0;
> > +}
> > +
> > +static int dp_pm_runtime_resume(struct device *dev)
> > +{
> > +       struct dp_display_private *dp = dev_get_dp_display_private(dev);
> > +
> > +       dp_display_host_init(dp);
> > +       if (dp->dp_display.is_edp) {
> > +               dp_catalog_ctrl_hpd_enable(dp->catalog);
> > +               dp_display_host_phy_init(dp);
> > +       }
> > +
> >          return 0;
> >   }
> >
> > @@ -1389,6 +1425,7 @@ static int dp_pm_suspend(struct device *dev)
> >   }
> >
> >   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,
> >   };
> > @@ -1473,10 +1510,6 @@ static int dp_display_get_next_bridge(struct msm_dp *dp)
> >          aux_bus = of_get_child_by_name(dev->of_node, "aux-bus");
> >
> >          if (aux_bus && dp->is_edp) {
> > -               dp_display_host_init(dp_priv);
> > -               dp_catalog_ctrl_hpd_enable(dp_priv->catalog);
> > -               dp_display_host_phy_init(dp_priv);
> > -
> >                  /*
> >                   * The code below assumes that the panel will finish probing
> >                   * by the time devm_of_dp_aux_populate_ep_devices() returns.
> > @@ -1578,6 +1611,11 @@ void dp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
> >                  dp_hpd_plug_handle(dp_display, 0);
> >
> >          mutex_lock(&dp_display->event_mutex);
> > +       if (pm_runtime_resume_and_get(&dp_display->pdev->dev)) {
> > +               DRM_ERROR("failed to start power\n");
> failed to resume.
>
> > +               mutex_unlock(&dp_display->event_mutex);
> > +               return;
> > +       }
> >
> >          state = dp_display->hpd_state;
> >          if (state != ST_DISPLAY_OFF && state != ST_MAINLINK_READY) {
> > @@ -1642,10 +1680,9 @@ void dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
> >          mutex_lock(&dp_display->event_mutex);
> >
> >          state = dp_display->hpd_state;
> > -       if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED) {
> > -               mutex_unlock(&dp_display->event_mutex);
> > -               return;
> > -       }
> > +       if (state != ST_DISCONNECT_PENDING && state != ST_CONNECTED)
> > +               drm_dbg_dp(dp->drm_dev, "type=%d wrong hpd_state=%d\n",
> > +                          dp->connector_type, state);
> >
> >          dp_display_disable(dp_display);
> >
> > @@ -1658,6 +1695,9 @@ void dp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
> >          }
> >
> >          drm_dbg_dp(dp->drm_dev, "type=%d Done\n", dp->connector_type);
> > +
> > +       pm_runtime_mark_last_busy(&dp_display->pdev->dev);
> > +       pm_runtime_put_autosuspend(&dp_display->pdev->dev);
> >          mutex_unlock(&dp_display->event_mutex);
> >   }
> >
> > @@ -1697,6 +1737,12 @@ void dp_bridge_hpd_enable(struct drm_bridge *bridge)
> >          struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
> >
> >          mutex_lock(&dp->event_mutex);
> > +       if (pm_runtime_resume_and_get(&dp->pdev->dev)) {
> > +               DRM_ERROR("failed to start power\n");
> > +               mutex_unlock(&dp->event_mutex);
> > +               return;
> > +       }
> > +
> >          dp_catalog_ctrl_hpd_enable(dp->catalog);
> >
> >          /* enable HDP interrupts */
> > @@ -1718,6 +1764,9 @@ void dp_bridge_hpd_disable(struct drm_bridge *bridge)
> >          dp_catalog_ctrl_hpd_disable(dp->catalog);
> >
> >          dp_display->internal_hpd = false;
> > +
> > +       pm_runtime_mark_last_busy(&dp->pdev->dev);
> > +       pm_runtime_put_autosuspend(&dp->pdev->dev);
> >          mutex_unlock(&dp->event_mutex);
> >   }
> >
> > @@ -1732,13 +1781,11 @@ void dp_bridge_hpd_notify(struct drm_bridge *bridge,
> >          if (dp_display->internal_hpd)
> >                  return;
> >
> > -       if (!dp->core_initialized) {
> > -               drm_dbg_dp(dp->drm_dev, "not initialized\n");
> > -               return;
> > -       }
> > -
> > -       if (!dp_display->link_ready && status == connector_status_connected)
> > +       /* hpd through gpio */
> Lack of the comment might be better than the incorrect comment.
>
> > +       if (!dp_display->link_ready && status == connector_status_connected) {
> > +               dp->hpd_state = ST_DISCONNECTED;
> Is this also a part of pm_runtime support?

yes, this is for hpd_internal == false case.

The hpd_state need to be at init state.

> >                  dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
> > -       else if (dp_display->link_ready && status == connector_status_disconnected)
> > +       } else if (dp_display->link_ready && status == connector_status_disconnected) {
> >                  dp_add_event(dp, EV_HPD_UNPLUG_INT, 0, 0);
> > +       }
> >   }
> > diff --git a/drivers/gpu/drm/msm/dp/dp_power.c b/drivers/gpu/drm/msm/dp/dp_power.c
> > index 5cb84ca..863c766 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_power.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_power.c
> > @@ -152,20 +152,9 @@ 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);
> >   }
> >
> > -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)
> >   {
> >          int rc = 0;
> > @@ -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;
> >   }
> > @@ -189,7 +174,6 @@ 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;
> >   }
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_power.h b/drivers/gpu/drm/msm/dp/dp_power.h
> > index a3dec20..55ada51 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_power.h
> > +++ b/drivers/gpu/drm/msm/dp/dp_power.h
> > @@ -81,17 +81,6 @@ int dp_power_clk_enable(struct dp_power *power, enum dp_pm_type pm_type,
> >   int dp_power_client_init(struct dp_power *power);
> >
> >   /**
> > - * dp_power_clinet_deinit() - de-initialize clock and regulator modules
> > - *
> > - * @power: instance of power module
> > - * return: 0 for success, error for failure.
> > - *
> > - * This API will de-initialize the DisplayPort's clocks and regulator
> > - * modules.
> > - */
> > -void dp_power_client_deinit(struct dp_power *power);
> > -
> > -/**
> >    * dp_power_get() - configure and get the DisplayPort power module data
> >    *
> >    * @parser: instance of parser module
> > --
> > 2.7.4