On Sat, 16 Sept 2023 at 00:39, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
>
> Currently eDP population is done at msm_dp_modeset_init() which happen
> at binding time. Move eDP population to be done at display probe time
> so that probe deferral cases can be handled effectively.
> wait_for_hpd_asserted callback is added during drm_dp_aux_init()
> to ensure eDP's HPD is up before proceeding eDP population.
>
> Changes in v3:
> -- add done_probing callback into devm_of_dp_aux_populate_bus()
>
> 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, 64 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
> index 8fa93c5..79f0c6e 100644
> --- a/drivers/gpu/drm/msm/dp/dp_aux.c
> +++ b/drivers/gpu/drm/msm/dp/dp_aux.c
> @@ -507,6 +507,21 @@ 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)
> {
> @@ -530,6 +545,16 @@ 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.
> + */
Usual comment: this describes what, but should be documenting why.
> + 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;
Then the relevant code should be removed before a call to drm_dp_aux_register().
> + 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 b58cb02..886fae5 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -310,8 +310,6 @@ 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);
> @@ -1217,6 +1215,31 @@ static const struct msm_dp_desc *dp_display_get_desc(struct platform_device *pde
> return NULL;
> }
>
> +static int dp_auxbus_done_probe(struct drm_dp_aux *aux)
> +{
> + int rc;
> +
> + rc = component_add(aux->dev, &dp_display_comp_ops);
> + if (rc)
> + DRM_ERROR("eDP component add failed, rc=%d\n", rc);
> +
> + return rc;
> +}
> +
> +static int dp_display_auxbus_population(struct dp_display_private *dp)
> +{
> + 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");
device_node refcount leak.
But I think that the aux-bus existence check is incorrect here.
of_dp_aux_populate_bus() will check and return -ENODEV if there is no
aux-bus subnode.
And once you have dropped the aux_bus check, you can safely inline
this function.
> +
> + if (aux_bus)
> + ret = devm_of_dp_aux_populate_bus(dp->aux, dp_auxbus_done_probe);
> +
> + return ret;
> +}
> +
> static int dp_display_probe(struct platform_device *pdev)
> {
> int rc = 0;
> @@ -1282,10 +1305,16 @@ static int dp_display_probe(struct platform_device *pdev)
> if (rc)
> return rc;
>
> - rc = component_add(&pdev->dev, &dp_display_comp_ops);
> - if (rc) {
> - DRM_ERROR("component add failed, rc=%d\n", rc);
> - dp_display_deinit_sub_modules(dp);
> + if (dp->dp_display.is_edp) {
> + rc = dp_display_auxbus_population(dp);
> + if (rc)
> + DRM_ERROR("eDP auxbus population failed, rc=%d\n", rc);
> + } else {
> + rc = component_add(&pdev->dev, &dp_display_comp_ops);
> + if (rc) {
> + DRM_ERROR("component add failed, rc=%d\n", rc);
> + dp_display_deinit_sub_modules(dp);
> + }
> }
>
> return rc;
> @@ -1296,14 +1325,13 @@ 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_put_sync_suspend(&pdev->dev);
> pm_runtime_dont_use_autosuspend(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
>
> + dp_display_deinit_sub_modules(dp);
These changes should be reasoned.
> +
> return 0;
> }
>
> @@ -1432,31 +1460,10 @@ 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;
Is there a need to set it to 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
> @@ -1469,17 +1476,9 @@ 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;
> }
>
> --
> 2.7.4
>
--
With best wishes
Dmitry
