drm: bridge: dw_hdmi: fix preference of RGB modes over YUV420

stable inclusion
from stable-v5.10.159
commit 6c788c0a250667089eebbd75be559c04876961b9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7NTXH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6c788c0a250667089eebbd75be559c04876961b9

--------------------------------

[ Upstream commit d3d6b1bf ]

Cheap monitors sometimes advertise YUV modes they don't really have
(HDMI specification mandates YUV support so even monitors without actual
support will often wrongfully advertise it) which results in YUV matches
and user forum complaints of a red tint to light colour display areas in
common desktop environments.

Moving the default RGB fall-back before YUV selection results in RGB
mode matching in most cases, reducing complaints.

Fixes: 6c3c7199 ("drm/bridge: synopsys: dw-hdmi: add bus format negociation")
Signed-off-by: NGuillaume BRUN <the.cheaterman@gmail.com>
Tested-by: NChristian Hewitt <christianshewitt@gmail.com>
Reviewed-by: NRobert Foss <robert.foss@linaro.org>
Signed-off-by: NNeil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221116143523.2126-1-the.cheaterman@gmail.comSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

@@ -2609,6 +2609,9 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
 	 * if supported. In any case the default RGB888 format is added
 	 */
 
+	/* Default 8bit RGB fallback */
+	output_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+
 	if (max_bpc >= 16 && info->bpc == 16) {
 		if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
 			output_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;
@@ -2642,9 +2645,6 @@ static u32 *dw_hdmi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
 	if (info->color_formats & DRM_COLOR_FORMAT_YCRCB444)
 		output_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
 
-	/* Default 8bit RGB fallback */
-	output_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
-
 	*num_output_fmts = i;
 
 	return output_fmts;