Re: [PATCH v7 5/7] drm/msm/dp: incorporate pm_runtime framework into DP driver

From: Dmitry Baryshkov
Date: Wed Oct 11 2023 - 21:02:15 EST


On 07/10/2023 01:55, Kuogee Hsieh wrote:
Currently DP driver is executed independent of PM runtime framework.
This leads msm eDP panel can not being detected by edp_panel driver
during generic_edp_panel_probe() due to AUX DPCD read failed at
edp panel driver. Incorporate PM runtime framework into DP driver so
that host controller's power and clocks are enable/disable through
PM runtime mechanism. Once PM runtime framework is incorporated into
DP driver, waking up device from power up path is not necessary. Hence
remove it.

After incorporating pm_runtime framework into eDP/DP driver,
dp_pm_suspend() to handle power off both DP phy and controller during
suspend and dp_pm_resume() to handle power on both DP phy and controller
during resume are not necessary. Therefore both dp_pm_suspend() and
dp_pm_resume() are dropped and replace with dp_pm_runtime_suspend() and
dp_pm_runtime_resume() respectively.

Changes in v7:
-- add comments to dp_pm_runtime_resume()
-- add comments to dp_bridge_hpd_enable()
-- delete dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_notify()

Changes in v6:
-- delete dp_power_client_deinit(dp->power);
-- remove if (!dp->dp_display.is_edp) condition checkout at plug_handle()
-- remove if (!dp->dp_display.is_edp) condition checkout at unplug_handle()
-- add IRQF_NO_AUTOEN to devm_request_irq()
-- add enable_irq() and disable_irq() to pm_runtime_resume()/suspend()
-- del dp->hpd_state = ST_DISCONNECTED from dp_bridge_hpd_disable()

Changes in v5:
-- remove pm_runtime_put_autosuspend feature, use pm_runtime_put_sync()
-- squash add pm_runtime_force_suspend()/resume() patch into this patch

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
-- drop both dp_pm_prepare() and dp_pm_compete() from this change
-- delete ST_SUSPENDED state
-- rewording commit text to add more details regrading the purpose
of this change

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
-- replace dp_pm_suspend() with pm_runtime_force_suspend()
-- replace dp_pm_resume() with pm_runtime_force_resume()

Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_aux.c | 5 +
drivers/gpu/drm/msm/dp/dp_display.c | 177 ++++++++++++++----------------------
drivers/gpu/drm/msm/dp/dp_power.c | 16 ----
drivers/gpu/drm/msm/dp/dp_power.h | 11 ---
4 files changed, 72 insertions(+), 137 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_aux.c b/drivers/gpu/drm/msm/dp/dp_aux.c
index 8e3b677..10b6eeb 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 +368,7 @@ static ssize_t dp_aux_transfer(struct drm_dp_aux *dp_aux,
exit:
mutex_unlock(&aux->mutex);
+ pm_runtime_put_sync(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 89fad67..acda544 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -49,7 +49,6 @@ enum {
ST_CONNECTED,
ST_DISCONNECT_PENDING,
ST_DISPLAY_OFF,
- ST_SUSPENDED,
};
enum {
@@ -310,10 +309,6 @@ 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);
@@ -558,7 +553,7 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
dp->dp_display.connector_type, state);
- if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
+ if (state == ST_DISPLAY_OFF) {
mutex_unlock(&dp->event_mutex);
return 0;
}
@@ -575,6 +570,12 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
return 0;
}
+ ret = pm_runtime_resume_and_get(&dp->pdev->dev);
+ if (ret) {
+ DRM_ERROR("failed to pm_runtime_resume\n");
+ return ret;
+ }
+
ret = dp_display_usbpd_configure_cb(&dp->pdev->dev);
if (ret) { /* link train failed */
dp->hpd_state = ST_DISCONNECTED;
@@ -657,6 +658,7 @@ static int dp_hpd_unplug_handle(struct dp_display_private *dp, u32 data)
dp->dp_display.connector_type, state);
/* uevent will complete disconnection part */
+ pm_runtime_put_sync(&dp->pdev->dev);
mutex_unlock(&dp->event_mutex);
return 0;
}
@@ -672,7 +674,7 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
drm_dbg_dp(dp->drm_dev, "Before, type=%d hpd_state=%d\n",
dp->dp_display.connector_type, state);
- if (state == ST_DISPLAY_OFF || state == ST_SUSPENDED) {
+ if (state == ST_DISPLAY_OFF) {
mutex_unlock(&dp->event_mutex);
return 0;
}
@@ -1085,7 +1087,6 @@ 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);
@@ -1177,7 +1178,9 @@ static int dp_display_request_irq(struct dp_display_private *dp)
}
rc = devm_request_irq(dev, dp->irq, dp_display_irq_handler,
- IRQF_TRIGGER_HIGH, "dp_display_isr", dp);
+ IRQF_TRIGGER_HIGH|IRQF_NO_AUTOEN,
+ "dp_display_isr", dp);
+
if (rc < 0) {
DRM_ERROR("failed to request IRQ%u: %d\n",
dp->irq, rc);
@@ -1263,6 +1266,10 @@ 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)
+ goto err;
+
rc = dp_display_request_irq(dp);
if (rc)
goto err;
@@ -1285,7 +1292,6 @@ 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_power_client_deinit(dp->power);
dp_display_deinit_sub_modules(dp);
platform_set_drvdata(pdev, NULL);
@@ -1293,109 +1299,47 @@ static int dp_display_remove(struct platform_device *pdev)
return 0;
}
-static int dp_pm_resume(struct device *dev)
+static int dp_pm_runtime_suspend(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct msm_dp *dp_display = platform_get_drvdata(pdev);
- struct dp_display_private *dp;
- int sink_count = 0;
-
- dp = container_of(dp_display, struct dp_display_private, dp_display);
-
- mutex_lock(&dp->event_mutex);
-
- drm_dbg_dp(dp->drm_dev,
- "Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
- dp->dp_display.connector_type, dp->core_initialized,
- dp->phy_initialized, dp_display->power_on);
-
- /* start from disconnected state */
- dp->hpd_state = ST_DISCONNECTED;
-
- /* turn on dp ctrl/phy */
- dp_display_host_init(dp);
-
- if (dp_display->is_edp)
- dp_catalog_ctrl_hpd_enable(dp->catalog);
+ struct dp_display_private *dp = dev_get_dp_display_private(dev);
- if (dp_catalog_link_is_connected(dp->catalog)) {
- /*
- * set sink to normal operation mode -- D0
- * before dpcd read
- */
- dp_display_host_phy_init(dp);
- dp_link_psm_config(dp->link, &dp->panel->link_info, false);
- sink_count = drm_dp_read_sink_count(dp->aux);
- if (sink_count < 0)
- sink_count = 0;
+ disable_irq(dp->irq);
+ if (dp->dp_display.is_edp) {
dp_display_host_phy_exit(dp);
+ dp_catalog_ctrl_hpd_disable(dp->catalog);
}
-
- dp->link->sink_count = sink_count;
- /*
- * can not declared display is connected unless
- * HDMI cable is plugged in and sink_count of
- * dongle become 1
- * also only signal audio when disconnected
- */
- if (dp->link->sink_count) {
- dp->dp_display.link_ready = true;
- } else {
- dp->dp_display.link_ready = false;
- dp_display_handle_plugged_change(dp_display, false);
- }
-
- drm_dbg_dp(dp->drm_dev,
- "After, type=%d sink=%d conn=%d core_init=%d phy_init=%d power=%d\n",
- dp->dp_display.connector_type, dp->link->sink_count,
- dp->dp_display.link_ready, dp->core_initialized,
- dp->phy_initialized, dp_display->power_on);
-
- mutex_unlock(&dp->event_mutex);
+ dp_display_host_deinit(dp);
return 0;
}
-static int dp_pm_suspend(struct device *dev)
+static int dp_pm_runtime_resume(struct device *dev)
{
- struct platform_device *pdev = to_platform_device(dev);
- struct msm_dp *dp_display = platform_get_drvdata(pdev);
- struct dp_display_private *dp;
-
- dp = container_of(dp_display, struct dp_display_private, dp_display);
-
- mutex_lock(&dp->event_mutex);
-
- drm_dbg_dp(dp->drm_dev,
- "Before, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
- dp->dp_display.connector_type, dp->core_initialized,
- dp->phy_initialized, dp_display->power_on);
-
- /* mainlink enabled */
- if (dp_power_clk_status(dp->power, DP_CTRL_PM))
- dp_ctrl_off_link_stream(dp->ctrl);
-
- dp_display_host_phy_exit(dp);
-
- /* host_init will be called at pm_resume */
- dp_display_host_deinit(dp);
-
- dp->hpd_state = ST_SUSPENDED;
-
- drm_dbg_dp(dp->drm_dev,
- "After, type=%d core_inited=%d phy_inited=%d power_on=%d\n",
- dp->dp_display.connector_type, dp->core_initialized,
- dp->phy_initialized, dp_display->power_on);
+ struct dp_display_private *dp = dev_get_dp_display_private(dev);
- mutex_unlock(&dp->event_mutex);
+ /*
+ * for eDP, host cotroller, HPD block and PHY are enabled here
+ * but with HPD irq disabled
+ *
+ * for DP, only host controller is enabled here.
+ * HPD block is enabled at dp_bridge_hpd_enable()
+ * PHY will be enabled at plugin handler later
+ */
+ dp_display_host_init(dp);
+ if (dp->dp_display.is_edp) {
+ dp_catalog_ctrl_hpd_enable(dp->catalog);
+ dp_display_host_phy_init(dp);
+ }
+ enable_irq(dp->irq);
return 0;
}
static const struct dev_pm_ops dp_pm_ops = {
- .suspend = dp_pm_suspend,
- .resume = dp_pm_resume,
+ SET_RUNTIME_PM_OPS(dp_pm_runtime_suspend, dp_pm_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
};
static struct platform_driver dp_display_driver = {
@@ -1478,10 +1422,6 @@ 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.
@@ -1583,6 +1523,11 @@ 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 pm_runtime_resume\n");
+ mutex_unlock(&dp_display->event_mutex);
+ return;
+ }
state = dp_display->hpd_state;
if (state != ST_DISPLAY_OFF && state != ST_MAINLINK_READY) {
@@ -1647,10 +1592,9 @@ 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);
@@ -1663,6 +1607,8 @@ 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_put_sync(&dp_display->pdev->dev);
mutex_unlock(&dp_display->event_mutex);
}
@@ -1701,7 +1647,21 @@ void dp_bridge_hpd_enable(struct drm_bridge *bridge)
struct msm_dp *dp_display = dp_bridge->dp_display;
struct dp_display_private *dp = container_of(dp_display, struct dp_display_private, dp_display);
+ /*
+ * this is for external DP with hpd irq enabled case,
+ * step-1: dp_pm_runtime_resume() enable dp host only
+ * step-2: enable hdp block and have hpd irq enabled here
+ * step-3: waiting for plugin irq while phy is not initialized
+ * step-4: DP PHY is initialized at plugin handler before link training
+ *
+ */
mutex_lock(&dp->event_mutex);
+ if (pm_runtime_resume_and_get(&dp->pdev->dev)) {
+ DRM_ERROR("failed to resume power\n");
+ mutex_unlock(&dp->event_mutex);
+ return;
+ }
+
dp_catalog_ctrl_hpd_enable(dp->catalog);
/* enable HDP interrupts */
@@ -1723,6 +1683,8 @@ void dp_bridge_hpd_disable(struct drm_bridge *bridge)
dp_catalog_ctrl_hpd_disable(dp->catalog);
dp_display->internal_hpd = false;
+
+ pm_runtime_put_sync(&dp->pdev->dev);
mutex_unlock(&dp->event_mutex);
}
@@ -1737,11 +1699,6 @@ 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)
dp_add_event(dp, EV_HPD_PLUG_INT, 0, 0);
else if (dp_display->link_ready && status == connector_status_disconnected)
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);

With W=1 I'm getting the following warnings:

drivers/gpu/drm/msm/dp/dp_power.c: In function ‘dp_power_init’:
drivers/gpu/drm/msm/dp/dp_power.c:161:34: warning: variable ‘power’ set but not used [-Wunused-but-set-variable]

-
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);

drivers/gpu/drm/msm/dp/dp_power.c: In function ‘dp_power_deinit’:
drivers/gpu/drm/msm/dp/dp_power.c:172:34: warning: variable ‘power’ set but not used [-Wunused-but-set-variable]


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

--
With best wishes
Dmitry