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.warn | 219 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 219 insertions(+) create mode 100644 scripts/Makefile.warn (limited to 'scripts/Makefile.warn') diff --git a/scripts/Makefile.warn b/scripts/Makefile.warn new file mode 100644 index 000000000..35af7d6c6 --- /dev/null +++ b/scripts/Makefile.warn @@ -0,0 +1,219 @@ +# SPDX-License-Identifier: GPL-2.0 +# ========================================================================== +# make W=... settings +# +# There are four warning groups enabled by W=1, W=2, W=3, and W=e +# They are independent, and can be combined like W=12 or W=123e. +# ========================================================================== + +# Default set of warnings, always enabled +KBUILD_CFLAGS += -Wall +KBUILD_CFLAGS += -Wextra +KBUILD_CFLAGS += -Wundef +KBUILD_CFLAGS += -Werror=implicit-function-declaration +KBUILD_CFLAGS += -Werror=implicit-int +KBUILD_CFLAGS += -Werror=return-type +KBUILD_CFLAGS += -Werror=strict-prototypes +KBUILD_CFLAGS += -Wno-format-security +KBUILD_CFLAGS += -Wno-trigraphs +KBUILD_CFLAGS += -Wno-frame-address +KBUILD_CFLAGS += $(call cc-option, -Wno-address-of-packed-member) +KBUILD_CFLAGS += -Wmissing-declarations +KBUILD_CFLAGS += -Wmissing-prototypes + +ifneq ($(CONFIG_FRAME_WARN),0) +KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN) +endif + +KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds + +ifdef CONFIG_CC_IS_CLANG +# Clang checks for overflow/truncation with '%p', while GCC does not: +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111219 +KBUILD_CFLAGS += $(call cc-option, -Wno-format-overflow-non-kprintf) +KBUILD_CFLAGS += $(call cc-option, -Wno-format-truncation-non-kprintf) + +# Clang may emit a warning when a const variable, such as the dummy variables +# in typecheck(), or const member of an aggregate type are not initialized, +# which can result in unexpected behavior. However, in many audited cases of +# the "field" variant of the warning, this is intentional because the field is +# never used within a particular call path, the field is within a union with +# other non-const members, or the containing object is not const so the field +# can be modified via memcpy() / memset(). While the variable warning also gets +# disabled with this same switch, there should not be too much coverage lost +# because -Wuninitialized will still flag when an uninitialized const variable +# is used. +KBUILD_CFLAGS += $(call cc-option, -Wno-default-const-init-unsafe) +else + +# gcc inanely warns about local variables called 'main' +KBUILD_CFLAGS += -Wno-main +endif + +# Too noisy on range checks and in macros handling both signed and unsigned. +KBUILD_CFLAGS += -Wno-type-limits + +# These result in bogus false positives +KBUILD_CFLAGS += $(call cc-option, -Wno-dangling-pointer) + +# Stack Variable Length Arrays (VLAs) must not be used in the kernel. +# Function array parameters should, however, be usable, but -Wvla will +# warn for those. Clang has no way yet to distinguish between the VLA +# types, so depend on GCC for now to keep stack VLAs out of the tree. +# https://github.com/llvm/llvm-project/issues/57098 +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98217 +KBUILD_CFLAGS += $(call cc-option,-Wvla-larger-than=1) + +# disable pointer signed / unsigned warnings in gcc 4.0 +KBUILD_CFLAGS += -Wno-pointer-sign + +# In order to make sure new function cast mismatches are not introduced +# in the kernel (to avoid tripping CFI checking), the kernel should be +# globally built with -Wcast-function-type. +KBUILD_CFLAGS += -Wcast-function-type + +# Currently, disable -Wstringop-overflow for GCC 11, globally. +KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow) +KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow) + +# Currently, disable -Wunterminated-string-initialization as broken +KBUILD_CFLAGS += $(call cc-option, -Wno-unterminated-string-initialization) + +# The allocators already balk at large sizes, so silence the compiler +# warnings for bounds checks involving those possible values. While +# -Wno-alloc-size-larger-than would normally be used here, earlier versions +# of gcc (<9.1) weirdly don't handle the option correctly when _other_ +# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX +# doesn't work (as it is documented to), silently resolving to "0" prior to +# version 9.1 (and producing an error more recently). Numeric values larger +# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently +# ignored, continuing to default to PTRDIFF_MAX. So, left with no other +# choice, we must perform a versioned check to disable this warning. +# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au +KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than +KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH) + +# Prohibit date/time macros, which would make the build non-deterministic +KBUILD_CFLAGS += -Werror=date-time + +# enforce correct pointer usage +KBUILD_CFLAGS += -Werror=incompatible-pointer-types + +# Require designated initializers for all marked structures +KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init) + +# Warn if there is an enum types mismatch +KBUILD_CFLAGS += $(call cc-option,-Wenum-conversion) + +KBUILD_CFLAGS += -Wunused + +# +# W=1 - warnings which may be relevant and do not occur too often +# +ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Wmissing-format-attribute +KBUILD_CFLAGS += -Wmissing-include-dirs +KBUILD_CFLAGS += -Wunused-const-variable + +KBUILD_CPPFLAGS += -Wundef +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN1 + +else + +# Some diagnostics enabled by default are noisy. +# Suppress them by using -Wno... except for W=1. +KBUILD_CFLAGS += -Wno-unused-but-set-variable +KBUILD_CFLAGS += -Wno-unused-const-variable +KBUILD_CFLAGS += $(call cc-option, -Wno-packed-not-aligned) +KBUILD_CFLAGS += $(call cc-option, -Wno-format-overflow) +ifdef CONFIG_CC_IS_GCC +KBUILD_CFLAGS += -Wno-format-truncation +endif +KBUILD_CFLAGS += $(call cc-option, -Wno-stringop-truncation) + +KBUILD_CFLAGS += -Wno-override-init # alias for -Wno-initializer-overrides in clang + +ifdef CONFIG_CC_IS_CLANG +KBUILD_CFLAGS += -Wno-pointer-to-enum-cast +KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare +KBUILD_CFLAGS += -Wno-unaligned-access +KBUILD_CFLAGS += -Wno-enum-compare-conditional +endif + +endif + +# +# W=2 - warnings which occur quite often but may still be relevant +# +ifneq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Wdisabled-optimization +KBUILD_CFLAGS += -Wshadow +KBUILD_CFLAGS += $(call cc-option, -Wlogical-op) +KBUILD_CFLAGS += -Wunused-macros + +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN2 + +else + +# The following turn off the warnings enabled by -Wextra +KBUILD_CFLAGS += -Wno-missing-field-initializers +KBUILD_CFLAGS += -Wno-shift-negative-value + +ifdef CONFIG_CC_IS_CLANG +KBUILD_CFLAGS += -Wno-enum-enum-conversion +endif + +ifdef CONFIG_CC_IS_GCC +KBUILD_CFLAGS += -Wno-maybe-uninitialized +endif + +endif + +# +# W=3 - more obscure warnings, can most likely be ignored +# +ifneq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) + +KBUILD_CFLAGS += -Wbad-function-cast +KBUILD_CFLAGS += -Wcast-align +KBUILD_CFLAGS += -Wcast-qual +KBUILD_CFLAGS += -Wconversion +KBUILD_CFLAGS += -Wpacked +KBUILD_CFLAGS += -Wpadded +KBUILD_CFLAGS += -Wpointer-arith +KBUILD_CFLAGS += -Wredundant-decls +KBUILD_CFLAGS += -Wsign-compare +KBUILD_CFLAGS += -Wswitch-default + +KBUILD_CPPFLAGS += -DKBUILD_EXTRA_WARN3 + +else + +# The following turn off the warnings enabled by -Wextra +KBUILD_CFLAGS += -Wno-sign-compare +KBUILD_CFLAGS += -Wno-unused-parameter + +endif + +# +# W=e and CONFIG_WERROR - error out on warnings +# +ifneq ($(findstring e, $(KBUILD_EXTRA_WARN))$(CONFIG_WERROR),) + +KBUILD_CPPFLAGS += -Werror +KBUILD_AFLAGS += -Wa,--fatal-warnings +KBUILD_LDFLAGS += --fatal-warnings +KBUILD_USERCFLAGS += -Werror +KBUILD_USERLDFLAGS += -Wl,--fatal-warnings +KBUILD_RUSTFLAGS += -Dwarnings + +# While hostprog flags are used during build bootstrapping (thus should not +# depend on CONFIG_ symbols), -Werror is disruptive and should be opted into. +# Only apply -Werror to hostprogs built after the initial Kconfig stage. +KBUILD_HOSTCFLAGS += -Werror +KBUILD_HOSTLDFLAGS += -Wl,--fatal-warnings +KBUILD_HOSTRUSTFLAGS += -Dwarnings + +endif -- cgit v1.3.1