Re: [PATCH v1 5/5] drm/msm/dp: move of_dp_aux_populate_bus() to probe for eDP
From: Dmitry Baryshkov
Date: Thu Jul 20 2023 - 18:20:32 EST
On 20/07/2023 23:27, Kuogee Hsieh wrote:
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@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.
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
If the 'dev' is the issue, you can always use dp_display_private::pdev.
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)
I might be missing something. Please describe, what exactly doesn't work.
+
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