From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- scripts/dtc/dtx_diff | 361 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 361 insertions(+) create mode 100755 scripts/dtc/dtx_diff (limited to 'scripts/dtc/dtx_diff') diff --git a/scripts/dtc/dtx_diff b/scripts/dtc/dtx_diff new file mode 100755 index 000000000..f2bbde4bb --- /dev/null +++ b/scripts/dtc/dtx_diff @@ -0,0 +1,361 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0-only + +# Copyright (C) 2015 Frank Rowand +# + + +usage() { + + # use spaces instead of tabs in the usage message + cat >&2 <tmp_dtx_1.dts + `basename $0` ARCH=arch_of_dtx_2 DTx_2 >tmp_dtx_2.dts + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts + rm tmp_dtx_1.dts tmp_dtx_2.dts + + If DTx_1 and DTx_2 are in different directories, then this script will + add the path of DTx_1 and DTx_2 to the include paths. If DTx_2 includes + a local file that exists in both the path of DTx_1 and DTx_2 then the + file in the path of DTx_1 will incorrectly be included. Possible + workaround: + + `basename $0` DTx_1 >tmp_dtx_1.dts + `basename $0` DTx_2 >tmp_dtx_2.dts + `basename $0` tmp_dtx_1.dts tmp_dtx_2.dts + rm tmp_dtx_1.dts tmp_dtx_2.dts + +eod +} + + +compile_to_dts() { + + dtx="$1" + dtc_include="$2" + + if [ -d "${dtx}" ] ; then + + # ----- input is file tree + + if ( ! ${DTC} -I fs ${dtx} ) ; then + exit 3 + fi + + elif [ -f "${dtx}" ] && [ -r "${dtx}" ] ; then + + magic=`hexdump -n 4 -e '/1 "%02x"' ${dtx}` + if [ "${magic}" = "d00dfeed" ] ; then + + # ----- input is FDT (binary blob) + + if ( ! ${DTC} -I dtb ${dtx} ) ; then + exit 3 + fi + + return + + fi + + # ----- input is DTS (source) + + if ( cpp ${cpp_flags} -x assembler-with-cpp ${dtx} \ + | ${DTC} ${dtc_include} -I dts ) ; then + return + fi + + echo "" >&2 + echo "Possible hints to resolve the above error:" >&2 + echo " (hints might not fix the problem)" >&2 + + hint_given=0 + + if [ "${ARCH}" = "" ] ; then + hint_given=1 + echo "" >&2 + echo " shell variable \$ARCH not set" >&2 + fi + + dtx_arch=`echo "/${dtx}" | sed -e 's|.*/arch/||' -e 's|/.*||'` + + if [ "${dtx_arch}" != "" -a "${dtx_arch}" != "${ARCH}" ] ; then + hint_given=1 + echo "" >&2 + echo " architecture ${dtx_arch} is in file path," >&2 + echo " but does not match shell variable \$ARCH" >&2 + echo " >>\$ARCH<< is: >>${ARCH}<<" >&2 + fi + + if [ ! -d ${srctree}/arch/${ARCH} ] ; then + hint_given=1 + echo "" >&2 + echo " ${srctree}/arch/${ARCH}/ does not exist" >&2 + echo " Is \$ARCH='${ARCH}' correct?" >&2 + echo " Possible fix: use '-s' option" >&2 + + git_root=`git rev-parse --show-toplevel 2>/dev/null` + if [ -d ${git_root}/arch/ ] ; then + echo " Possible fix: use '-S' option" >&2 + fi + fi + + if [ $hint_given = 0 ] ; then + echo "" >&2 + echo " No hints available." >&2 + fi + + echo "" >&2 + + exit 3 + + else + echo "" >&2 + echo "ERROR: ${dtx} does not exist or is not readable" >&2 + echo "" >&2 + exit 2 + fi + +} + + +# ----- start of script + +annotate="" +cmd_diff=0 +diff_flags="-u" +diff_color="" +dtx_file_1="" +dtx_file_2="" +dtc_sort="-s" +help=0 +srctree="" + + +while [ $# -gt 0 ] ; do + + case $1 in + + -c | --color ) + if diff --color /dev/null /dev/null 2>/dev/null ; then + diff_color="--color=always" + fi + shift + ;; + + -f ) + diff_flags="--unified=999999" + shift + ;; + + -h | -help | --help ) + help=1 + shift + ;; + + -s ) + srctree="$2" + shift 2 + ;; + + -S ) + git_root=`git rev-parse --show-toplevel 2>/dev/null` + srctree="${git_root}" + shift + ;; + + -T | --annotate ) + if [ "${annotate}" = "" ] ; then + annotate="-T" + elif [ "${annotate}" = "-T" ] ; then + annotate="-T -T" + fi + shift + ;; + -u ) + dtc_sort="" + shift + ;; + + *) + if [ "${dtx_file_1}" = "" ] ; then + dtx_file_1="$1" + elif [ "${dtx_file_2}" = "" ] ; then + dtx_file_2="$1" + else + echo "" >&2 + echo "ERROR: Unexpected parameter: $1" >&2 + echo "" >&2 + exit 2 + fi + shift + ;; + + esac + +done + +if [ "${srctree}" = "" ] ; then + srctree="." +fi + +if [ "${dtx_file_2}" != "" ]; then + cmd_diff=1 +fi + +if (( ${help} )) ; then + usage + exit 1 +fi + +# this must follow check for ${help} +if [ "${dtx_file_1}" = "" ]; then + echo "" >&2 + echo "ERROR: parameter DTx required" >&2 + echo "" >&2 + exit 2 +fi + + +# ----- prefer dtc from linux kernel, allow fallback to dtc in $PATH + +if [ "${KBUILD_OUTPUT:0:2}" = ".." ] ; then + __KBUILD_OUTPUT="${srctree}/${KBUILD_OUTPUT}" +elif [ "${KBUILD_OUTPUT}" = "" ] ; then + __KBUILD_OUTPUT="." +else + __KBUILD_OUTPUT="${KBUILD_OUTPUT}" +fi + +DTC="${__KBUILD_OUTPUT}/scripts/dtc/dtc" + +if [ ! -x ${DTC} ] ; then + __DTC="dtc" + if grep -q "^CONFIG_DTC=y" ${__KBUILD_OUTPUT}/.config 2>/dev/null; then + make_command=' + make scripts' + else + make_command=' + Enable CONFIG_DTC in the kernel configuration + make scripts' + fi + if ( ! which ${__DTC} >/dev/null ) ; then + + # use spaces instead of tabs in the error message + cat >&2 <