openwrt/target/linux/bcm27xx/patches-6.1/950-0697-drm-vc4-Limit-max_bpc-to-8-on-Pi0-3.patch

From d1e78bb6380ca89d0b00ab60d65d9f34f346b6fe Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Mon, 24 Apr 2023 18:32:45 +0100
Subject: [PATCH] drm/vc4: Limit max_bpc to 8 on Pi0-3

Pi 0-3 have no deep colour support and only 24bpp output,
so max_bpc should remain as 8.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -783,7 +783,6 @@ static int vc4_hdmi_connector_init(struc
 
 	drm_connector_attach_colorspace_property(connector);
 	drm_connector_attach_tv_margin_properties(connector);
-	drm_connector_attach_max_bpc_property(connector, 8, 12);
 
 	connector->polled = (DRM_CONNECTOR_POLL_CONNECT |
 			     DRM_CONNECTOR_POLL_DISCONNECT);
@@ -792,8 +791,12 @@ static int vc4_hdmi_connector_init(struc
 	connector->doublescan_allowed = 0;
 	connector->stereo_allowed = 1;
 
-	if (vc4_hdmi->variant->supports_hdr)
+	if (vc4_hdmi->variant->supports_hdr) {
+		drm_connector_attach_max_bpc_property(connector, 8, 12);
 		drm_connector_attach_hdr_output_metadata_property(connector);
+	} else {
+		drm_connector_attach_max_bpc_property(connector, 8, 8);
+	}
 
 	vc4_hdmi_attach_broadcast_rgb_property(dev, vc4_hdmi);
 	vc4_hdmi_attach_output_format_property(dev, vc4_hdmi);