drm/msm/dp: promote irq_hpd handle to handle link training correctly

Some dongles require link training done at irq_hpd request instead
of plugin request. This patch promote irq_hpd handler to handle link
training and setup hpd_state correctly.
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

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

@@ -449,10 +449,9 @@ 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) {
-		dp_add_event(dp, EV_USER_NOTIFICATION, false, 0);
 		if (dp_display_is_sink_count_zero(dp)) {
 			DRM_DEBUG_DP("sink count is zero, nothing to do\n");
-			return 0;
+			return -ENOTCONN;
 		}
 
 		return dp_display_process_hpd_high(dp);
@@ -469,7 +468,9 @@ static int dp_display_handle_irq_hpd(struct dp_display_private *dp)
 static int dp_display_usbpd_attention_cb(struct device *dev)
 {
 	int rc = 0;
+	u32 sink_request;
 	struct dp_display_private *dp;
+	struct dp_usbpd *hpd;
 
 	if (!dev) {
 		DRM_ERROR("invalid dev\n");
@@ -483,10 +484,26 @@ static int dp_display_usbpd_attention_cb(struct device *dev)
 		return -ENODEV;
 	}
 
+	hpd = dp->usbpd;
+
 	/* check for any test request issued by sink */
 	rc = dp_link_process_request(dp->link);
-	if (!rc)
-		dp_display_handle_irq_hpd(dp);
+	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;
+		}
+	}
 
 	return rc;
 }