[PATCH v1 5/5] drm/msm/dp: move of_dp_aux_populate_bus() to probe for eDP
Kuogee Hsieh
quic_khsieh at quicinc.com
Thu Jul 20 20:27:34 UTC 2023
On 7/10/2023 11:24 AM, Dmitry Baryshkov wrote:
> [Restored CC list]
>
> On Mon, 10 Jul 2023 at 20:08, Kuogee Hsieh <quic_khsieh at quicinc.com> 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 at quicinc.com>
>>>> ---
>>>> 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.
sorry for late response,
yes, pm_runtime_enable() at probe() is better and i did that original.
but it is not work.
I found that,
1) at dp_display_bind(), dev is mdss
2) at probe() dev is dp
3) pm_runtime_enable(dp's dev) and generic_edp_panel_probe() -->
pm_runtime_get_sync(mdss's dev)
>>>> +
>>>> 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;
>>>> }
>
>
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