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

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

Fixes: 6c6e8b2e04d5 ("drm/msm/dp: promote irq_hpd handle to handle link training correctly")
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>

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

@@ -279,13 +279,25 @@ 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;
+	static bool encoder_mode_set;
+
+	if (!encoder_mode_set && dp->dp_display.encoder &&
+				kms->funcs->set_encoder_mode) {
+		kms->funcs->set_encoder_mode(kms,
+				dp->dp_display.encoder, false);
 
+		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 +310,6 @@ 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;
@@ -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);
@@ -448,15 +453,6 @@ static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
 
 	sink_request = dp->link->sink_request;
 
-	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;
-		}
-
-		return dp_display_process_hpd_high(dp);
-	}
-
 	dp_ctrl_handle_sink_request(dp->ctrl);
 
 	if (dp->link->sink_request & DP_TEST_LINK_VIDEO_PATTERN)
@@ -491,17 +487,29 @@ static int dp_display_usbpd_attention_cb(struct device *dev)
 	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 (dp_display_is_sink_count_zero(dp)) {
+				DRM_DEBUG_DP("sink count is zero, nothing to do\n");
+				if (dp->hpd_state != ST_DISCONNECTED) {
+					hpd->hpd_high = 0;
+					dp->hpd_state = ST_DISCONNECT_PENDING;
+					dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
+				}
+				rc = -ENOTCONN;
+			} else {
+				if (dp->hpd_state == ST_DISCONNECTED) {
+					hpd->hpd_high = 1;
+					dp->hpd_state = ST_CONNECT_PENDING;
+
+					rc = dp_display_process_hpd_high(dp);
+					if (rc) {
+						hpd->hpd_high = 0;
+						dp->hpd_state = ST_DISCONNECTED;
+					}
+				}
+			}
+		} else {
+			if (!dp_display_is_ds_bridge(dp->panel))
+				rc = dp_display_handle_irq_hpd(dp);
 		}
 	}
 
@@ -668,6 +676,7 @@ 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 +687,10 @@ 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);