openwrt/target/linux/bcm27xx/patches-5.15/950-0643-drm-vc4-hdmi-Fix-no-video-output-on-DVI-monitors.patch

From 64c3b233b38af0817c70d142c65b915ca1fbc71a Mon Sep 17 00:00:00 2001
From: Matthias Reichl <hias@horus.com>
Date: Thu, 30 Dec 2021 15:12:19 +0100
Subject: [PATCH] drm/vc4: hdmi: Fix no video output on DVI monitors

The drm edid parser doesn't signal RGB support on DVI monitors
with old edid versions, leading to 8-bit RGB mode being rejected
and no video on DVI monitors.

As 8-bit RGB is mandatory on HDMI and DVI monitors anyways we can
simply drop the RGB format check, aligning vc4 with other drivers.

Signed-off-by: Matthias Reichl <hias@horus.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 3 ---
 1 file changed, 3 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1416,9 +1416,6 @@ vc4_hdmi_sink_supports_format_bpc(const
 	case VC4_HDMI_OUTPUT_RGB:
 		drm_dbg(dev, "RGB Format, checking the constraints.\n");
 
-		if (!(info->color_formats & DRM_COLOR_FORMAT_RGB444))
-			return false;
-
 		if (bpc == 10 && !(info->edid_hdmi_rgb444_dc_modes & DRM_EDID_HDMI_DC_30)) {
 			drm_dbg(dev, "10 BPC but sink doesn't support Deep Color 30.\n");
 			return false;