1 files changed, 88 insertions, 31 deletions

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 5606bca3caa8..61d5c57f23e1 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -795,6 +795,86 @@ void drm_kms_helper_poll_fini(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 
+static bool check_connector_changed(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	enum drm_connector_status old_status;
+	u64 old_epoch_counter;
+
+	/* Only handle HPD capable connectors. */
+	drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
+
+	drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
+
+	old_status = connector->status;
+	old_epoch_counter = connector->epoch_counter;
+	connector->status = drm_helper_probe_detect(connector, NULL, false);
+
+	if (old_epoch_counter == connector->epoch_counter) {
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
+			    connector->base.id,
+			    connector->name,
+			    connector->epoch_counter);
+
+		return false;
+	}
+
+	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
+		    connector->base.id,
+		    connector->name,
+		    drm_get_connector_status_name(old_status),
+		    drm_get_connector_status_name(connector->status));
+
+	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
+		    connector->base.id,
+		    connector->name,
+		    old_epoch_counter,
+		    connector->epoch_counter);
+
+	return true;
+}
+
+/**
+ * drm_connector_helper_hpd_irq_event - hotplug processing
+ * @connector: drm_connector
+ *
+ * Drivers can use this helper function to run a detect cycle on a connector
+ * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
+ *
+ * This helper function is useful for drivers which can track hotplug
+ * interrupts for a single connector. Drivers that want to send a
+ * hotplug event for all connectors or can't track hotplug interrupts
+ * per connector need to use drm_helper_hpd_irq_event().
+ *
+ * This function must be called from process context with no mode
+ * setting locks held.
+ *
+ * Note that a connector can be both polled and probed from the hotplug
+ * handler, in case the hotplug interrupt is known to be unreliable.
+ *
+ * Returns:
+ * A boolean indicating whether the connector status changed or not
+ */
+bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
+{
+	struct drm_device *dev = connector->dev;
+	bool changed;
+
+	mutex_lock(&dev->mode_config.mutex);
+	changed = check_connector_changed(connector);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	if (changed) {
+		drm_kms_helper_hotplug_event(dev);
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
+			    connector->base.id,
+			    connector->name);
+	}
+
+	return changed;
+}
+EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
+
 /**
  * drm_helper_hpd_irq_event - hotplug processing
  * @dev: drm_device
@@ -808,23 +888,25 @@ EXPORT_SYMBOL(drm_kms_helper_poll_fini);
  * interrupts for each connector.
  *
  * Drivers which support hotplug interrupts for each connector individually and
- * which have a more fine-grained detect logic should bypass this code and
- * directly call drm_kms_helper_hotplug_event() in case the connector state
- * changed.
+ * which have a more fine-grained detect logic can use
+ * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
+ * code and directly call drm_kms_helper_hotplug_event() in case the connector
+ * state changed.
  *
  * This function must be called from process context with no mode
  * setting locks held.
  *
  * Note that a connector can be both polled and probed from the hotplug handler,
  * in case the hotplug interrupt is known to be unreliable.
+ *
+ * Returns:
+ * A boolean indicating whether the connector status changed or not
  */
 bool drm_helper_hpd_irq_event(struct drm_device *dev)
 {
 	struct drm_connector *connector;
 	struct drm_connector_list_iter conn_iter;
-	enum drm_connector_status old_status;
 	bool changed = false;
-	u64 old_epoch_counter;
 
 	if (!dev->mode_config.poll_enabled)
 		return false;
@@ -836,33 +918,8 @@ bool drm_helper_hpd_irq_event(struct drm_device *dev)
 		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
 			continue;
 
-		old_status = connector->status;
-
-		old_epoch_counter = connector->epoch_counter;
-
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Old epoch counter %llu\n", connector->base.id,
-			      connector->name,
-			      old_epoch_counter);
-
-		connector->status = drm_helper_probe_detect(connector, NULL, false);
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
-			      connector->base.id,
-			      connector->name,
-			      drm_get_connector_status_name(old_status),
-			      drm_get_connector_status_name(connector->status));
-
-		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] New epoch counter %llu\n",
-			      connector->base.id,
-			      connector->name,
-			      connector->epoch_counter);
-
-		/*
-		 * Check if epoch counter had changed, meaning that we need
-		 * to send a uevent.
-		 */
-		if (old_epoch_counter != connector->epoch_counter)
+		if (check_connector_changed(connector))
 			changed = true;
-
 	}
 	drm_connector_list_iter_end(&conn_iter);
 	mutex_unlock(&dev->mode_config.mutex);