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/Makefile.modpost | 157 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 scripts/Makefile.modpost (limited to 'scripts/Makefile.modpost') diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost new file mode 100644 index 000000000..d7d45067d --- /dev/null +++ b/scripts/Makefile.modpost @@ -0,0 +1,157 @@ +# SPDX-License-Identifier: GPL-2.0 +# =========================================================================== +# Module versions +# =========================================================================== +# +# Stage one of module building created the following: +# a) The individual .o files used for the module +# b) A .o file which is the .o files above linked together +# c) A .mod file, listing the name of the preliminary .o file, +# plus all .o files +# d) modules.order, which lists all the modules + +# Stage 2 is handled by this file and does the following +# 1) Find all modules listed in modules.order +# 2) modpost is then used to +# 3) create one .mod.c file per module +# 4) create one Module.symvers file with CRC for all exported symbols + +# Step 3 is used to place certain information in the module's ELF +# section, including information such as: +# Version magic (see include/linux/vermagic.h for full details) +# - Kernel release +# - SMP is CONFIG_SMP +# - PREEMPT is CONFIG_PREEMPT[_RT] +# - GCC Version +# Module info +# - Module version (MODULE_VERSION) +# - Module alias'es (MODULE_ALIAS) +# - Module license (MODULE_LICENSE) +# - See include/linux/module.h for more details + +# Step 4 is solely used to allow module versioning in external modules, +# where the CRC of each module is retrieved from the Module.symvers file. + +PHONY := __modpost +__modpost: + +include $(objtree)/include/config/auto.conf +include $(srctree)/scripts/Kbuild.include + +MODPOST = $(objtree)/scripts/mod/modpost + +modpost-args = \ + $(if $(CONFIG_MODULES),-M) \ + $(if $(CONFIG_MODVERSIONS),-m) \ + $(if $(CONFIG_BASIC_MODVERSIONS),-b) \ + $(if $(CONFIG_EXTENDED_MODVERSIONS),-x) \ + $(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \ + $(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \ + $(if $(KBUILD_MODPOST_WARN),-w) \ + $(if $(KBUILD_NSDEPS),-d modules.nsdeps) \ + $(if $(CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS)$(KBUILD_NSDEPS),-N) \ + $(if $(findstring 1, $(KBUILD_EXTRA_WARN)),-W) \ + -o $@ + +modpost-deps := $(MODPOST) + +# 'make -i -k' ignores compile errors, and builds as many modules as possible. +ifneq ($(findstring i,$(filter-out --%,$(MAKEFLAGS))),) +modpost-args += -n +endif + +# Read out modules.order to pass in modpost. +# Otherwise, allmodconfig would fail with "Argument list too long". +ifdef KBUILD_MODULES +modpost-args += -T modules.order +modpost-deps += modules.order +endif + +ifeq ($(KBUILD_EXTMOD),) + +# Generate the list of in-tree objects in vmlinux +# --------------------------------------------------------------------------- + +# This is used to retrieve symbol versions generated by genksyms. +ifdef CONFIG_MODVERSIONS +vmlinux.symvers Module.symvers: .vmlinux.objs +endif + +# Ignore libgcc.a +# Some architectures do '$(CC) --print-libgcc-file-name' to borrow libgcc.a +# from the toolchain, but there is no EXPORT_SYMBOL in it. + +quiet_cmd_vmlinux_objs = GEN $@ + cmd_vmlinux_objs = \ + for f in $(real-prereqs); do \ + case $${f} in \ + *libgcc.a) ;; \ + *) $(AR) t $${f} ;; \ + esac \ + done > $@ + +targets += .vmlinux.objs +.vmlinux.objs: vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE + $(call if_changed,vmlinux_objs) + +ifdef CONFIG_TRIM_UNUSED_KSYMS +ksym-wl := $(CONFIG_UNUSED_KSYMS_WHITELIST) +ksym-wl := $(if $(filter-out /%, $(ksym-wl)),$(if $(wildcard $(ksym-wl)),,$(srctree)/))$(ksym-wl) +modpost-args += -t $(addprefix -u , $(ksym-wl)) +modpost-deps += $(ksym-wl) +endif + +ifeq ($(wildcard vmlinux.o),) +missing-input := vmlinux.o +output-symdump := modules-only.symvers +else +modpost-args += vmlinux.o +modpost-deps += vmlinux.o +output-symdump := $(if $(KBUILD_MODULES), Module.symvers, vmlinux.symvers) +endif + +else + +# set src + obj - they may be used in the modules's Makefile +obj := . +src := $(srcroot) + +# Include the module's Makefile to find KBUILD_EXTRA_SYMBOLS +include $(kbuild-file) + +output-symdump := Module.symvers + +ifeq ($(wildcard $(objtree)/Module.symvers),) +missing-input := $(objtree)/Module.symvers +else +modpost-args += -i $(objtree)/Module.symvers +modpost-deps += $(objtree)/Module.symvers +endif + +modpost-args += -e $(addprefix -i , $(KBUILD_EXTRA_SYMBOLS)) + +endif # ($(KBUILD_EXTMOD),) + +quiet_cmd_modpost = MODPOST $@ + cmd_modpost = \ + $(if $(missing-input), \ + echo >&2 "WARNING: $(missing-input) is missing."; \ + echo >&2 " Modules may not have dependencies or modversions."; \ + echo >&2 " You may get many unresolved symbol errors."; \ + echo >&2 " You can set KBUILD_MODPOST_WARN=1 to turn errors into warning"; \ + echo >&2 " if you want to proceed at your own risk.";) \ + $(MODPOST) $(modpost-args) + +targets += $(output-symdump) +$(output-symdump): $(modpost-deps) FORCE + $(call if_changed,modpost) + +__modpost: $(output-symdump) +PHONY += FORCE +FORCE: + +existing-targets := $(wildcard $(sort $(targets))) + +-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) + +.PHONY: $(PHONY) -- cgit v1.3.1