drm/amd/display: Refactor amdgpu_dm_connector_detect (v2)

Prepare for polling analog connectors.
Document the function better.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Timur Kristóf

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -7226,29 +7226,32 @@ create_stream_for_sink(struct drm_connector *connector,
 	return stream;
 }
 
+/**
+ * amdgpu_dm_connector_detect() - Detect whether a DRM connector is connected to a display
+ *
+ * A connector is considered connected when it has a sink that is not NULL.
+ * For connectors that support HPD (hotplug detection), the connection is
+ * handled in the HPD interrupt.
+ *
+ * Notes:
+ * 1. This interface is NOT called in context of HPD irq.
+ * 2. This interface *is called* in context of user-mode ioctl. Which
+ *    makes it a bad place for *any* MST-related activity.
+ */
 static enum drm_connector_status
 amdgpu_dm_connector_detect(struct drm_connector *connector, bool force)
 {
-	bool connected;
 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
 
-	/*
-	 * Notes:
-	 * 1. This interface is NOT called in context of HPD irq.
-	 * 2. This interface *is called* in context of user-mode ioctl. Which
-	 * makes it a bad place for *any* MST-related activity.
-	 */
-
-	if (aconnector->base.force == DRM_FORCE_UNSPECIFIED &&
-	    !aconnector->fake_enable)
-		connected = (aconnector->dc_sink != NULL);
-	else
-		connected = (aconnector->base.force == DRM_FORCE_ON ||
-				aconnector->base.force == DRM_FORCE_ON_DIGITAL);
-
 	update_subconnector_property(aconnector);
 
-	return (connected ? connector_status_connected :
+	if (aconnector->base.force == DRM_FORCE_ON ||
+		aconnector->base.force == DRM_FORCE_ON_DIGITAL)
+		return connector_status_connected;
+	else if (aconnector->base.force == DRM_FORCE_OFF)
+		return connector_status_disconnected;
+
+	return (aconnector->dc_sink ? connector_status_connected :
 			connector_status_disconnected);
 }