drm/msm/dp: fix connect/disconnect handled at irq_hpd

Some usb type-c dongle use irq_hpd request to perform device connection
and disconnection. This patch add handling of both connection and
disconnection are based on the state of hpd_state and sink_count.

Changes in V2:
-- add dp_display_handle_port_ststus_changed()
-- fix kernel test robot complaint

Changes in V3:
-- add encoder_mode_set into struct dp_display_private
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 26b8d66a ("drm/msm/dp: promote irq_hpd handle to handle link training correctly")
Tested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dp/dp_display.c

@@ -102,6 +102,8 @@ struct dp_display_private {
 	struct dp_display_mode dp_mode;
 	struct msm_dp dp_display;
 
+	bool encoder_mode_set;
+
 	/* wait for audio signaling */
 	struct completion audio_comp;
 
@@ -279,13 +281,24 @@ static void dp_display_send_hpd_event(struct msm_dp *dp_display)
 	drm_helper_hpd_irq_event(connector->dev);
 }
 
-static int dp_display_send_hpd_notification(struct dp_display_private *dp,
-					    bool hpd)
+
+static void dp_display_set_encoder_mode(struct dp_display_private *dp)
 {
-	static bool encoder_mode_set;
 	struct msm_drm_private *priv = dp->dp_display.drm_dev->dev_private;
 	struct msm_kms *kms = priv->kms;
 
+	if (!dp->encoder_mode_set && dp->dp_display.encoder &&
+				kms->funcs->set_encoder_mode) {
+		kms->funcs->set_encoder_mode(kms,
+				dp->dp_display.encoder, false);
+
+		dp->encoder_mode_set = true;
+	}
+}
+
+static int dp_display_send_hpd_notification(struct dp_display_private *dp,
+					    bool hpd)
+{
 	if ((hpd && dp->dp_display.is_connected) ||
 			(!hpd && !dp->dp_display.is_connected)) {
 		DRM_DEBUG_DP("HPD already %s\n", (hpd ? "on" : "off"));
@@ -298,15 +311,6 @@ static int dp_display_send_hpd_notification(struct dp_display_private *dp,
 
 	dp->dp_display.is_connected = hpd;
 
-	if (dp->dp_display.is_connected && dp->dp_display.encoder
-				&& !encoder_mode_set
-				&& kms->funcs->set_encoder_mode) {
-		kms->funcs->set_encoder_mode(kms,
-				dp->dp_display.encoder, false);
-		DRM_DEBUG_DP("set_encoder_mode() Completed\n");
-		encoder_mode_set = true;
-	}
-
 	dp_display_send_hpd_event(&dp->dp_display);
 
 	return 0;
@@ -342,7 +346,6 @@ static int dp_display_process_hpd_high(struct dp_display_private *dp)
 
 	dp_add_event(dp, EV_USER_NOTIFICATION, true, 0);
 
-
 end:
 	return rc;
 }
@@ -359,6 +362,8 @@ static void dp_display_host_init(struct dp_display_private *dp)
 	if (dp->usbpd->orientation == ORIENTATION_CC2)
 		flip = true;
 
+	dp_display_set_encoder_mode(dp);
+
 	dp_power_init(dp->power, flip);
 	dp_ctrl_host_init(dp->ctrl, flip);
 	dp_aux_init(dp->aux);
@@ -442,24 +447,42 @@ static void dp_display_handle_video_request(struct dp_display_private *dp)
 	}
 }
 
-static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
+static int dp_display_handle_port_ststus_changed(struct dp_display_private *dp)
 {
-	u32 sink_request;
-
-	sink_request = dp->link->sink_request;
+	int rc = 0;
 
-	if (sink_request & DS_PORT_STATUS_CHANGED) {
-		if (dp_display_is_sink_count_zero(dp)) {
-			DRM_DEBUG_DP("sink count is zero, nothing to do\n");
-			return -ENOTCONN;
+	if (dp_display_is_sink_count_zero(dp)) {
+		DRM_DEBUG_DP("sink count is zero, nothing to do\n");
+		if (dp->hpd_state != ST_DISCONNECTED) {
+			dp->hpd_state = ST_DISCONNECT_PENDING;
+			dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
+		}
+	} else {
+		if (dp->hpd_state == ST_DISCONNECTED) {
+			dp->hpd_state = ST_CONNECT_PENDING;
+			rc = dp_display_process_hpd_high(dp);
+			if (rc)
+				dp->hpd_state = ST_DISCONNECTED;
 		}
+	}
+
+	return rc;
+}
+
+static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
+{
+	u32 sink_request = dp->link->sink_request;
 
-		return dp_display_process_hpd_high(dp);
+	if (dp->hpd_state == ST_DISCONNECTED) {
+		if (sink_request & DP_LINK_STATUS_UPDATED) {
+			DRM_ERROR("Disconnected, no DP_LINK_STATUS_UPDATED\n");
+			return -EINVAL;
+		}
 	}
 
 	dp_ctrl_handle_sink_request(dp->ctrl);
 
-	if (dp->link->sink_request & DP_TEST_LINK_VIDEO_PATTERN)
+	if (sink_request & DP_TEST_LINK_VIDEO_PATTERN)
 		dp_display_handle_video_request(dp);
 
 	return 0;
@@ -490,19 +513,10 @@ static int dp_display_usbpd_attention_cb(struct device *dev)
 	rc = dp_link_process_request(dp->link);
 	if (!rc) {
 		sink_request = dp->link->sink_request;
-		if (sink_request & DS_PORT_STATUS_CHANGED) {
-			/* same as unplugged */
-			hpd->hpd_high = 0;
-			dp->hpd_state = ST_DISCONNECT_PENDING;
-			dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
-		}
-
-		rc = dp_display_handle_irq_hpd(dp);
-
-		if (!rc && (sink_request & DS_PORT_STATUS_CHANGED)) {
-			hpd->hpd_high = 1;
-			dp->hpd_state = ST_CONNECT_PENDING;
-		}
+		if (sink_request & DS_PORT_STATUS_CHANGED)
+			rc = dp_display_handle_port_ststus_changed(dp);
+		else
+			rc = dp_display_handle_irq_hpd(dp);
 	}
 
 	return rc;
@@ -668,6 +682,7 @@ static int dp_disconnect_pending_timeout(struct dp_display_private *dp, u32 data
 static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
 {
 	u32 state;
+	int ret;
 
 	mutex_lock(&dp->event_mutex);
 
@@ -678,7 +693,10 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
 		return 0;
 	}
 
-	dp_display_usbpd_attention_cb(&dp->pdev->dev);
+	ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
+	if (ret == -ECONNRESET) { /* cable unplugged */
+		dp->core_initialized = false;
+	}
 
 	mutex_unlock(&dp->event_mutex);