drm/sun4i: rgb: Enable panel after controller

The panel should be enabled after the controller so that we do not have
visual glitches on the panel while the controller is setup. Similarly,
the panel should be disabled before the controller.

Signed-off-by: Jonathan Liu <net147@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_rgb.c

@@ -152,15 +152,16 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 
 	DRM_DEBUG_DRIVER("Enabling RGB output\n");
 
-	if (!IS_ERR(tcon->panel)) {
+	if (!IS_ERR(tcon->panel))
 		drm_panel_prepare(tcon->panel);
-		drm_panel_enable(tcon->panel);
-	}
 
 	/* encoder->bridge can be NULL; drm_bridge_enable checks for it */
 	drm_bridge_enable(encoder->bridge);
 
 	sun4i_tcon_channel_enable(tcon, 0);
+
+	if (!IS_ERR(tcon->panel))
+		drm_panel_enable(tcon->panel);
 }
 
 static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
@@ -171,15 +172,16 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 
 	DRM_DEBUG_DRIVER("Disabling RGB output\n");
 
+	if (!IS_ERR(tcon->panel))
+		drm_panel_disable(tcon->panel);
+
 	sun4i_tcon_channel_disable(tcon, 0);
 
 	/* encoder->bridge can be NULL; drm_bridge_disable checks for it */
 	drm_bridge_disable(encoder->bridge);
 
-	if (!IS_ERR(tcon->panel)) {
-		drm_panel_disable(tcon->panel);
+	if (!IS_ERR(tcon->panel))
 		drm_panel_unprepare(tcon->panel);
-	}
 }
 
 static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,