[Restored CC list]
On Mon, 10 Jul 2023 at 20:08, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
>
>
> On 7/7/2023 5:32 PM, Dmitry Baryshkov wrote:
> > On 08/07/2023 02:52, Kuogee Hsieh wrote:
> >> Move of_dp_aux_populate_bus() to dp_display_probe() for eDP
> >> from dp_display_bind() so that probe deferral cases can be
> >> handled effectively
> >>
> >> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/msm/dp/dp_aux.c | 25 ++++++++++++
> >> drivers/gpu/drm/msm/dp/dp_display.c | 79
> >> +++++++++++++++++++------------------
> >> 2 files changed, 65 insertions(+), 39 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c
> >> b/drivers/gpu/drm/msm/dp/dp_aux.c
> >> index c592064..c1baffb 100644
> >> --- a/drivers/gpu/drm/msm/dp/dp_aux.c
> >> +++ b/drivers/gpu/drm/msm/dp/dp_aux.c
> >> @@ -505,6 +505,21 @@ void dp_aux_unregister(struct drm_dp_aux *dp_aux)
> >> drm_dp_aux_unregister(dp_aux);
> >> }
> >> +static int dp_wait_hpd_asserted(struct drm_dp_aux *dp_aux,
> >> + unsigned long wait_us)
> >> +{
> >> + int ret;
> >> + struct dp_aux_private *aux;
> >> +
> >> + aux = container_of(dp_aux, struct dp_aux_private, dp_aux);
> >> +
> >> + pm_runtime_get_sync(aux->dev);
> >> + ret = dp_catalog_aux_wait_for_hpd_connect_state(aux->catalog);
> >> + pm_runtime_put_sync(aux->dev);
> >> +
> >> + return ret;
> >> +}
> >> +
> >> struct drm_dp_aux *dp_aux_get(struct device *dev, struct dp_catalog
> >> *catalog,
> >> bool is_edp)
> >> {
> >> @@ -528,6 +543,16 @@ struct drm_dp_aux *dp_aux_get(struct device
> >> *dev, struct dp_catalog *catalog,
> >> aux->catalog = catalog;
> >> aux->retry_cnt = 0;
> >> + /*
> >> + * Use the drm_dp_aux_init() to use the aux adapter
> >> + * before registering aux with the DRM device.
> >> + */
> >> + aux->dp_aux.name = "dpu_dp_aux";
> >> + aux->dp_aux.dev = dev;
> >> + aux->dp_aux.transfer = dp_aux_transfer;
> >> + aux->dp_aux.wait_hpd_asserted = dp_wait_hpd_asserted;
> >> + drm_dp_aux_init(&aux->dp_aux);
> >> +
> >> return &aux->dp_aux;
> >> }
> >> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c
> >> b/drivers/gpu/drm/msm/dp/dp_display.c
> >> index 185f1eb..7ed4bea 100644
> >> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> >> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> >> @@ -302,10 +302,6 @@ static int dp_display_bind(struct device *dev,
> >> struct device *master,
> >> goto end;
> >> }
> >> - pm_runtime_enable(dev);
> >> - pm_runtime_set_autosuspend_delay(dev, 1000);
> >> - pm_runtime_use_autosuspend(dev);
> >> -
> >> return 0;
> >> end:
> >> return rc;
> >> @@ -322,8 +318,6 @@ static void dp_display_unbind(struct device *dev,
> >> struct device *master,
> >> 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);
> >> @@ -1245,6 +1239,29 @@ static const struct msm_dp_desc
> >> *dp_display_get_desc(struct platform_device *pde
> >> return NULL;
> >> }
> >> +static void of_dp_aux_depopulate_bus_void(void *data)
> >> +{
> >> + of_dp_aux_depopulate_bus(data);
> >> +}
> >> +
> >> +static int dp_display_auxbus_emulation(struct dp_display_private *dp)
> >
> > Why is it called emulation?
> >
> >> +{
> >> + struct device *dev = &dp->pdev->dev;
> >> + struct device_node *aux_bus;
> >> + int ret = 0;
> >> +
> >> + aux_bus = of_get_child_by_name(dev->of_node, "aux-bus");
> >> +
> >> + if (aux_bus) {
> >> + ret = devm_of_dp_aux_populate_bus(dp->aux, NULL);
> >
> > And here you missed the whole point of why we have been asking for.
> > Please add a sensible `done_probing' callback, which will call
> > component_add(). This way the DP component will only be registered
> > when the panel has been probed. Keeping us from the component binding
> > retries and corresponding side effects.
> >
> >> +
> >> + devm_add_action_or_reset(dev, of_dp_aux_depopulate_bus_void,
> >> + dp->aux);
> >
> > Useless, it's already handled by the devm_ part of the
> > devm_of_dp_aux_populate_bus().
> >
> >> + }
> >> +
> >> + return ret;
> >> +}
> >> +
> >> static int dp_display_probe(struct platform_device *pdev)
> >> {
> >> int rc = 0;
> >> @@ -1290,8 +1307,18 @@ static int dp_display_probe(struct
> >> platform_device *pdev)
> >> platform_set_drvdata(pdev, &dp->dp_display);
> >> + pm_runtime_enable(&pdev->dev);
> >> + pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
> >> + pm_runtime_use_autosuspend(&pdev->dev);
> >
> > Can we have this in probe right from the patch #2?
>
> no, at patch#2, devm_of_dp_aux_populate_bus() is done ta bind timing.
>
> The device used by pm_runtime_get_sync() of generic_edp_panel_probe()
> which is derived from devm_of_dp_aux_populate_bus() is different the
> &pdev->dev here.
Excuse me, I don't get your answer. In patch #2 you have added
pm_runtime_enable() / etc to dp_display_bind().
In this patch you are moving these calls to dp_display_probe(). I
think that the latter is a better place for enabling runtime PM and as
such I've asked you to squash this chunk into patch #2.
Why isn't that going to work?
If I'm not mistaken here, the panel's call to pm_runtime_get_sync()
will wake up the panel and all the parent devices, including the DP.
That's what I meant in my comment regarding PM calls in the patch #1.
pm_runtime_get_sync() / resume() / etc. do not only increase the
runtime PM count. They do other things to parent devices, linked
devices, etc.
>
> >
> >> +
> >> dp_display_request_irq(dp);
> >> + if (dp->dp_display.is_edp) {
> >> + rc = dp_display_auxbus_emulation(dp);
> >> + if (rc)
> >> + DRM_ERROR("eDP aux-bus emulation failed, rc=%d\n", rc);
> >> + }
> >> +
> >> rc = component_add(&pdev->dev, &dp_display_comp_ops);
> >> if (rc) {
> >> DRM_ERROR("component add failed, rc=%d\n", rc);
> >> @@ -1306,11 +1333,14 @@ static int dp_display_remove(struct
> >> platform_device *pdev)
> >> struct dp_display_private *dp =
> >> dev_get_dp_display_private(&pdev->dev);
> >> component_del(&pdev->dev, &dp_display_comp_ops);
> >> - dp_display_deinit_sub_modules(dp);
> >> -
> >> platform_set_drvdata(pdev, NULL);
> >> +
> >> + pm_runtime_dont_use_autosuspend(&pdev->dev);
> >> + pm_runtime_disable(&pdev->dev);
> >> pm_runtime_put_sync_suspend(&pdev->dev);
> >> + dp_display_deinit_sub_modules(dp);
> >> +
> >> return 0;
> >> }
> >> @@ -1514,31 +1544,10 @@ void msm_dp_debugfs_init(struct msm_dp
> >> *dp_display, struct drm_minor *minor)
> >> static int dp_display_get_next_bridge(struct msm_dp *dp)
> >> {
> >> - int rc;
> >> + int rc = 0;
> >> struct dp_display_private *dp_priv;
> >> - struct device_node *aux_bus;
> >> - struct device *dev;
> >> dp_priv = container_of(dp, struct dp_display_private,
> >> dp_display);
> >> - dev = &dp_priv->pdev->dev;
> >> - aux_bus = of_get_child_by_name(dev->of_node, "aux-bus");
> >> -
> >> - if (aux_bus && dp->is_edp) {
> >> - /*
> >> - * The code below assumes that the panel will finish probing
> >> - * by the time devm_of_dp_aux_populate_ep_devices() returns.
> >> - * This isn't a great assumption since it will fail if the
> >> - * panel driver is probed asynchronously but is the best we
> >> - * can do without a bigger driver reorganization.
> >> - */
> >> - rc = of_dp_aux_populate_bus(dp_priv->aux, NULL);
> >> - of_node_put(aux_bus);
> >> - if (rc)
> >> - goto error;
> >> - } else if (dp->is_edp) {
> >> - DRM_ERROR("eDP aux_bus not found\n");
> >> - return -ENODEV;
> >> - }
> >> /*
> >> * External bridges are mandatory for eDP interfaces: one has to
> >> @@ -1551,17 +1560,9 @@ static int dp_display_get_next_bridge(struct
> >> msm_dp *dp)
> >> if (!dp->is_edp && rc == -ENODEV)
> >> return 0;
> >> - if (!rc) {
> >> + if (!rc)
> >> dp->next_bridge = dp_priv->parser->next_bridge;
> >> - return 0;
> >> - }
> >> -error:
> >> - if (dp->is_edp) {
> >> - of_dp_aux_depopulate_bus(dp_priv->aux);
> >> - dp_display_host_phy_exit(dp_priv);
> >> - dp_display_host_deinit(dp_priv);
> >> - }
> >> return rc;
> >> }
> >
--
With best wishes
Dmitry
