drm/msm/dp: return correct connection status after suspend/resume

diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index b15b4ce4ba35..4f3679b7e262 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_MASK;
+	status >>= DP_DP_HPD_STATE_STATUS_BITS_SHIFT;
+
+	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..1f16508d0387 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 */
@@ -1189,6 +1179,26 @@  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 dp_display_private *dp = platform_get_drvdata(pdev);
+	u32 status;
+
+	if (!dp) {
+		DRM_ERROR("DP driver bind failed. Invalid driver data\n");
+		return -EINVAL;
+	}
+
+	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;
+
 	return 0;
 }
 
@@ -1202,6 +1212,9 @@  static int dp_pm_suspend(struct device *dev)
 		return -EINVAL;
 	}
 
+	if (dp->core_initialized == true)
+		dp_display_disable(dp, 0);
+
 	atomic_set(&dp->hpd_state, ST_SUSPENDED);
 
 	return 0;
@@ -1317,19 +1330,6 @@  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 +1359,6 @@  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 +1380,6 @@  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)