[PATCH] drm/mediatek: make eDP panel as the first connected connector

[Gil Dekel]

Some userspace presumes that the first connected connector is the main
display, where it's supposed to display e.g. the login screen. For
laptops, this should be the main panel.

This patch call drm_helper_move_panel_connectors_to_head() after
drm_bridge_connector_init() to make sure eDP stay at head of
connected connector list. This fixes unexpected corruption happen
at eDP panel if eDP is not placed at head of connected connector
list.

Tested by ensuring the internal panels are at the top of the connector
list via modetest -c.

This patch does to mediatek what the following patch
https://www.spinics.net/lists/stable/msg590605.html
did to qualcomm.

Signed-off-by: Gil Dekel <gildekel at chromium.org>
Tested-by: Gil Dekel <gildekel at chromium.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 91f58db5915f..76daaf6a0945 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -386,6 +386,12 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 	if (ret)
 		goto put_mutex_dev;
 
+	/*
+	 * Ensure internal panels are at the top of the connector list before
+	 * crtc creation.
+	 */
+	drm_helper_move_panel_connectors_to_head(drm);
+
 	/*
 	 * We currently support two fixed data streams, each optional,
 	 * and each statically assigned to a crtc:
-- 
Gil Dekel, Software Engineer, Google / ChromeOS Display and Graphics