[PATCH v2] drm/msm/dp: return correct connection status after suspend

[PATCH v2] drm/msm/dp: return correct connection status after suspend

[Kuogee Hsieh]

At dp_pm_resume, reinitialize both dp host controller and hpd block
so that hpd connection can be detected at realtime by reading hpd state
status register. Also hpd plug interrupt can be generated accordingly.

Changes in v2:
-- use container_of to cast correct dp_display_private pointer
   at both dp_pm_suspend and dp_pm_resume.

Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
---
 drivers/gpu/drm/msm/dp/dp_catalog.c | 13 ++++++
 drivers/gpu/drm/msm/dp/dp_catalog.h |  1 +
 drivers/gpu/drm/msm/dp/dp_display.c | 67 ++++++++++++-----------------
 drivers/gpu/drm/msm/dp/dp_reg.h     |  2 +
 4 files changed, 43 insertions(+), 40 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index b15b4ce4ba35..63c5ada34c21 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -572,6 +572,19 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog)
 	dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, DP_DP_HPD_CTRL_HPD_EN);
 }
 
+u32 dp_catalog_hpd_get_state_status(struct dp_catalog *dp_catalog)
+{
+	struct dp_catalog_private *catalog = container_of(dp_catalog,
+				struct dp_catalog_private, dp_catalog);
+	u32 status = 0;
+
+	status = dp_read_aux(catalog, REG_DP_DP_HPD_INT_STATUS);
+	status >>= DP_DP_HPD_STATE_STATUS_BITS_SHIFT;
+	status &= DP_DP_HPD_STATE_STATUS_BITS_MASK;
+
+	return status;
+}
+
 u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog)
 {
 	struct dp_catalog_private *catalog = container_of(dp_catalog,
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
index 4b7666f1fe6f..6d257dbebf29 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.h
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
@@ -97,6 +97,7 @@ void dp_catalog_ctrl_enable_irq(struct dp_catalog *dp_catalog, bool enable);
 void dp_catalog_hpd_config_intr(struct dp_catalog *dp_catalog,
 			u32 intr_mask, bool en);
 void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog);
+u32 dp_catalog_hpd_get_state_status(struct dp_catalog *dp_catalog);
 u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog);
 void dp_catalog_ctrl_phy_reset(struct dp_catalog *dp_catalog);
 int dp_catalog_ctrl_update_vx_px(struct dp_catalog *dp_catalog, u8 v_level,
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index e175aa3fd3a9..431dff9de797 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -114,8 +114,6 @@ struct dp_display_private {
 	struct dp_event event_list[DP_EVENT_Q_MAX];
 	spinlock_t event_lock;
 
-	struct completion resume_comp;
-
 	struct dp_audio *audio;
 };
 
@@ -508,9 +506,6 @@ static int dp_hpd_plug_handle(struct dp_display_private *dp, u32 data)
 		return 0;
 	}
 
-	if (state == ST_SUSPENDED)
-		tout = DP_TIMEOUT_NONE;
-
 	atomic_set(&dp->hpd_state, ST_CONNECT_PENDING);
 
 	hpd->hpd_high = 1;
@@ -798,8 +793,6 @@ static int dp_display_enable(struct dp_display_private *dp, u32 data)
 	if (!rc)
 		dp_display->power_on = true;
 
-	/* complete resume_comp regardless it is armed or not */
-	complete(&dp->resume_comp);
 	return rc;
 }
 
@@ -1151,9 +1144,6 @@ static int dp_display_probe(struct platform_device *pdev)
 	}
 
 	mutex_init(&dp->event_mutex);
-
-	init_completion(&dp->resume_comp);
-
 	g_dp_display = &dp->dp_display;
 
 	/* Store DP audio handle inside DP display */
@@ -1189,18 +1179,40 @@ static int dp_display_remove(struct platform_device *pdev)
 
 static int dp_pm_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;
+	u32 status;
+
+	dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	dp_display_host_init(dp);
+
+	dp_catalog_ctrl_hpd_config(dp->catalog);
+
+	status = dp_catalog_hpd_get_state_status(dp->catalog);
+
+	if (status) {
+		dp->dp_display.is_connected = true;
+	} else {
+		dp->dp_display.is_connected = false;
+		/* make sure next resume host_init be called */
+		dp->core_initialized = false;
+	}
+
 	return 0;
 }
 
 static int dp_pm_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
-	struct dp_display_private *dp = platform_get_drvdata(pdev);
+	struct msm_dp *dp_display = platform_get_drvdata(pdev);
+	struct dp_display_private *dp;
 
-	if (!dp) {
-		DRM_ERROR("DP driver bind failed. Invalid driver data\n");
-		return -EINVAL;
-	}
+	dp = container_of(dp_display, struct dp_display_private, dp_display);
+
+	if (dp_display->power_on == true)
+		dp_display_disable(dp, 0);
 
 	atomic_set(&dp->hpd_state, ST_SUSPENDED);
 
@@ -1317,19 +1329,6 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
 	return 0;
 }
 
-static int dp_display_wait4resume_done(struct dp_display_private *dp)
-{
-	int ret = 0;
-
-	reinit_completion(&dp->resume_comp);
-	if (!wait_for_completion_timeout(&dp->resume_comp,
-				WAIT_FOR_RESUME_TIMEOUT_JIFFIES)) {
-		DRM_ERROR("wait4resume_done timedout\n");
-		ret = -ETIMEDOUT;
-	}
-	return ret;
-}
-
 int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
 {
 	int rc = 0;
@@ -1359,14 +1358,6 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
 	}
 
 	state =  atomic_read(&dp_display->hpd_state);
-	if (state == ST_SUSPENDED) {
-		/* start link training */
-		dp_add_event(dp_display, EV_HPD_PLUG_INT, 0, 0);
-		mutex_unlock(&dp_display->event_mutex);
-
-		/* wait until dp interface is up */
-		goto resume_done;
-	}
 
 	dp_display_enable(dp_display, 0);
 
@@ -1388,10 +1379,6 @@ int msm_dp_display_enable(struct msm_dp *dp, struct drm_encoder *encoder)
 	mutex_unlock(&dp_display->event_mutex);
 
 	return rc;
-
-resume_done:
-	dp_display_wait4resume_done(dp_display);
-	return rc;
 }
 
 int msm_dp_display_pre_disable(struct msm_dp *dp, struct drm_encoder *encoder)
diff --git a/drivers/gpu/drm/msm/dp/dp_reg.h b/drivers/gpu/drm/msm/dp/dp_reg.h
index 43042ff90a19..268602803d9a 100644
--- a/drivers/gpu/drm/msm/dp/dp_reg.h
+++ b/drivers/gpu/drm/msm/dp/dp_reg.h
@@ -32,6 +32,8 @@
 #define DP_DP_IRQ_HPD_INT_ACK			(0x00000002)
 #define DP_DP_HPD_REPLUG_INT_ACK		(0x00000004)
 #define DP_DP_HPD_UNPLUG_INT_ACK		(0x00000008)
+#define DP_DP_HPD_STATE_STATUS_BITS_MASK	(0x0000000F)
+#define DP_DP_HPD_STATE_STATUS_BITS_SHIFT	(0x1C)
 
 #define REG_DP_DP_HPD_INT_MASK			(0x0000000C)
 #define DP_DP_HPD_PLUG_INT_MASK			(0x00000001)

base-commit: 3c0f462da069af12211901ddf26f7e16e6951d9b
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v2] drm/msm/dp: return correct connection status after suspend

[Stephen Boyd]

Quoting Kuogee Hsieh (2020-09-26 13:34:54)
> At dp_pm_resume, reinitialize both dp host controller and hpd block

dp_pm_resume()

> so that hpd connection can be detected at realtime by reading hpd state
> status register. Also hpd plug interrupt can be generated accordingly.

Can you describe more here? The subject says "return correct connection
status after suspend" so it seems that suspend connection status is
broken. How is it broken? What can be done to see if it is broken? I
think you can suspend, disconnect the DP cable, and then resume and see
that the device is connected still?

What does "hpd plug interrupt can be generated accordingly" mean? Is the
interrupt not being generated?

> 
> Changes in v2:
> -- use container_of to cast correct dp_display_private pointer
>    at both dp_pm_suspend and dp_pm_resume.
> 
> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>

Any Fixes tag?

> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
> index b15b4ce4ba35..63c5ada34c21 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> @@ -572,6 +572,19 @@ void dp_catalog_ctrl_hpd_config(struct dp_catalog *dp_catalog)
>         dp_write_aux(catalog, REG_DP_DP_HPD_CTRL, DP_DP_HPD_CTRL_HPD_EN);
>  }
>  
> +u32 dp_catalog_hpd_get_state_status(struct dp_catalog *dp_catalog)
> +{
> +       struct dp_catalog_private *catalog = container_of(dp_catalog,
> +                               struct dp_catalog_private, dp_catalog);
> +       u32 status = 0;

We don't need to assign to 0 to reassign immediately after.

> +
> +       status = dp_read_aux(catalog, REG_DP_DP_HPD_INT_STATUS);
> +       status >>= DP_DP_HPD_STATE_STATUS_BITS_SHIFT;
> +       status &= DP_DP_HPD_STATE_STATUS_BITS_MASK;
> +
> +       return status;
> +}
> +
>  u32 dp_catalog_hpd_get_intr_status(struct dp_catalog *dp_catalog)
>  {
>         struct dp_catalog_private *catalog = container_of(dp_catalog,