drm/nouveau/disp: use drm_kms_helper_connector_hotplug_event()

This adds more information to the hotplug uevent and lets user-space
know that it's about a particular connector only.
Signed-off-by: Simon Ser <contact@emersion.fr>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230620181547.272476-1-contact@emersion.fr

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -465,7 +465,8 @@ nouveau_display_hpd_work(struct work_struct *work)
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
 	u32 pending;
-	bool changed = false;
+	int changed = 0;
+	struct drm_connector *first_changed_connector = NULL;
 
 	pm_runtime_get_sync(dev->dev);
 
@@ -509,7 +510,12 @@ nouveau_display_hpd_work(struct work_struct *work)
 		if (old_epoch_counter == connector->epoch_counter)
 			continue;
 
-		changed = true;
+		changed++;
+		if (!first_changed_connector) {
+			drm_connector_get(connector);
+			first_changed_connector = connector;
+		}
+
 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s (epoch counter %llu->%llu)\n",
 			    connector->base.id, connector->name,
 			    drm_get_connector_status_name(old_status),
@@ -520,9 +526,14 @@ nouveau_display_hpd_work(struct work_struct *work)
 	drm_connector_list_iter_end(&conn_iter);
 	mutex_unlock(&dev->mode_config.mutex);
 
-	if (changed)
+	if (changed == 1)
+		drm_kms_helper_connector_hotplug_event(first_changed_connector);
+	else if (changed > 0)
 		drm_kms_helper_hotplug_event(dev);
 
+	if (first_changed_connector)
+		drm_connector_put(first_changed_connector);
+
 	pm_runtime_mark_last_busy(drm->dev->dev);
 noop:
 	pm_runtime_put_autosuspend(dev->dev);