On Thu, Sep 30, 2021 at 9:02 AM Nathan Chancellor nathan@kernel.org wrote:

cc-ifversion only works for GCC, as clang pretends to be GCC 4.2.1 for glibc compatibility, which means IS_OLD_GCC will get set and unsupported flags will be passed to clang when building certain code within the DCN files:

clang-14: error: unknown argument: '-mpreferred-stack-boundary=4' make[5]: *** [scripts/Makefile.build:277: drivers/gpu/drm/amd/amdgpu/../display/dc/dcn201/dcn201_resource.o] Error 1

Guard the call to cc-ifversion with CONFIG_CC_IS_GCC so that everything continues to work properly. See commit 00db297106e8 ("drm/amdgpu: fix stack alignment ABI mismatch for GCC 7.1+") for more context.

Fixes: ff7e396f822f ("drm/amd/display: add cyan_skillfish display support") Link: https://github.com/ClangBuiltLinux/linux/issues/1468 Signed-off-by: Nathan Chancellor nathan@kernel.org

Thanks for the patch! Reviewed-by: Nick Desaulniers ndesaulniers@google.com

$ grep -rn "ifdef IS_OLD_GCC" drivers/gpu/drm/amd/display/dc/ | wc -l 11

It's probably time to put this pattern in a Makefile under scripts/ and include it in all of these Makefiles. Anything to minimize the amount of code that has to be carried forward to new subdirs.

---

drivers/gpu/drm/amd/display/dc/dcn201/Makefile | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn201/Makefile b/drivers/gpu/drm/amd/display/dc/dcn201/Makefile index d98d69705117..96cbd4ccd344 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn201/Makefile +++ b/drivers/gpu/drm/amd/display/dc/dcn201/Makefile @@ -14,9 +14,11 @@ ifdef CONFIG_PPC64 CFLAGS_$(AMDDALPATH)/dc/dcn201/dcn201_resource.o := -mhard-float -maltivec endif

+ifdef CONFIG_CC_IS_GCC ifeq ($(call cc-ifversion, -lt, 0701, y), y) IS_OLD_GCC = 1 endif +endif

ifdef CONFIG_X86 ifdef IS_OLD_GCC

base-commit: b47b99e30cca8906753c83205e8c6179045dd725

2.33.0.591.gddb1055343