Clang 21.1.0 and later fails to build target drivers/gpu/drm/amd/display/dc/* targets on Kernel 5.10 x86_64 because of -mhard-float

[ajordanr-google]

-mhard-float is not a valid Clang flag for x86_64 targets, but it's used in the AMD display driver code occasionally. We believe before LLVM commit a4b2f4a72aa9b4655ecc723838830e0a7f29c9ca, this flag was simply ignored when paired with -Qunused-arguments,
and did nothing. However, since a4b2f4a72aa9b4655ecc723838830e0a7f29c9ca, this is now treated as an
error:

clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_mode_lib.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_rq_dlg_helpers.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_rq_dlg_helpers.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dml1_display_rq_dlg_calc.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/dcn20_fpu.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_mode_vba.o
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dml1_display_rq_dlg_calc.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_rq_dlg_calc_20.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_mode_vba_20.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/dcn20_fpu.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_rq_dlg_calc_20v2.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_mode_vba_20v2.o
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_mode_vba_20.o] Error 1
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/display_mode_vba.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn21/display_rq_dlg_calc_21.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn21/display_mode_vba_21.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_rq_dlg_calc_20.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_rq_dlg_calc_20v2.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_rq_dlg_calc_30.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:287: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn21/display_rq_dlg_calc_21.o] Error 1
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn21/display_mode_vba_21.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn31/display_mode_vba_31.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn31/display_rq_dlg_calc_31.o
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn20/display_mode_vba_20v2.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dsc/rc_calc_fpu.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_init.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_hubp.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_hubbub.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_rq_dlg_calc_30.o] Error 1
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn31/display_mode_vba_31.o] Error 1
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn30/display_mode_vba_30.o] Error 1
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_resource.o
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn31/display_rq_dlg_calc_31.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_hwseq.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_link_encoder.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_dccg.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:286: drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dsc/rc_calc_fpu.o] Error 1
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_init.o
  CC      drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_hubbub.o
clang: error: unsupported option '-mhard-float' for target 'x86_64-cros-linux-gnu'
make[5]: *** [/mnt/host/source/src/third_party/kernel/v5.10/scripts/Makefile.build:287: drivers/gpu/drm/amd/amdgpu/../display/dc/dcn21/dcn21_resource.o] Error 1

Clang 20.1.0 Example (works)
Clang 21.1.0 Example (fails)

This is already fixed in newer Kernels, specifically v5.15 at d081467 already:

commit d08146795689a0b2563b1eec8e4b6f4d050b2453
Author: Nathan Chancellor <nathan@kernel.org>
Date:   Wed Jan 11 20:05:09 2023 -0700

    drm/amd/display: Do not add '-mhard-float' to dml_ccflags for clang

    commit 7db038d9790eda558dd6c1dde4cdd58b64789c47 upstream.

    When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
    warns:

      clang-16: error: argument unused during compilation: '-mhard-float' [-Werror,-Wunused-command-line-argument]

    Similar to commit 84edc2eff827 ("selftest/fpu: avoid clang warning"),
    just add this flag to GCC builds. Commit 0f0727d971f6 ("drm/amd/display:
    readd -msse2 to prevent Clang from emitting libcalls to undefined SW FP
    routines") added '-msse2' to prevent clang from emitting software
    floating point routines.

    Signed-off-by: Nathan Chancellor <nathan@kernel.org>
    Acked-by: Alex Deucher <alexander.deucher@amd.com>
    Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
    Tested-by: Anders Roxell <anders.roxell@linaro.org>
    Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
    Signed-off-by: Nathan Chancellor <nathan@kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
index 96e70832c742..36cac3839b50 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
@@ -26,7 +26,8 @@
 # subcomponents.

 ifdef CONFIG_X86
-dml_ccflags := -mhard-float -msse
+dml_ccflags-$(CONFIG_CC_IS_GCC) := -mhard-float
+dml_ccflags := $(dml_ccflags-y) -msse
 endif

 ifdef CONFIG_PPC6

Public ChromeOS Bug: https://issuetracker.google.com/491530865

[nickdesaulniers]

@nathanchance I asked @ajordanr-google to raise this issue here. FWICT, it sounds like CrOS was considering carrying a patch that sounds like is available in 5.15 LTS but not 5.10 LTS. Is this something that can get backported/sent to 5.10?

[nathanchance]

@nickdesaulniers Hmmm, interesting. It looks like there are additional places that add -mhard-float to CFLAGS in 5.10 that I missed with the 5.10 changes to avoid this (the change @ajordanr-google mentioned above is already present in 5.10):

https://git.kernel.org/stable/c/0c3939b002530b0e7d7443652d38fffa875bccd1
https://git.kernel.org/stable/c/80ecbebebfe80ab4127ef0c23abb57b809248fcc

Maybe allmodconfig does not build these files there because CI is fine right now.

[nickdesaulniers]

Your patches modify 3 sources. The patch the CrOS folks mention in comment 2 of the above thread touch 9 Makefiles.

[nathanchance]

Well it does not look like CrOS 5.10 has even merged up to my changes (landed in 5.10.239, it looks like they are on 5.10.237?) based on the diff in that bug (sorry, initially skipped opening it when it required a Google account sign in). It would be useful to know what errors remain with them applied because from what I can tell, only

diff --git a/drivers/gpu/drm/amd/display/dc/dsc/Makefile b/drivers/gpu/drm/amd/display/dc/dsc/Makefile
index 6207809f293b..4fc6d9c32d16 100644
--- a/drivers/gpu/drm/amd/display/dc/dsc/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dsc/Makefile
@@ -3,7 +3,8 @@
 # Makefile for the 'dsc' sub-component of DAL.

 ifdef CONFIG_X86
-dsc_ccflags := -mhard-float -msse
+dsc_ccflags-$(CONFIG_CC_IS_GCC) := -mhard-float
+dsc_ccflags := $(dsc_ccflags-y) -msse
 endif

 ifdef CONFIG_PPC64

would still be needed based on the error logs?

[ajordanr-google]

Thanks Nathan! That's a good question, we may just be missing your changes on our branch. Will test now.

I do think the patch Deva wrote is a bit overzelous in its changes, and in practice it's likely 1-2 file changes actually.

[nickdesaulniers]

it looks like they are on 5.10.237?

Looks like the latest release of 5.10 is 5.10.252:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/Makefile?h=v5.10.252

yikes, I wonder why they're so behind?

[ajordanr-google]

Double checked, and indeed we are missing your patches, Nathan.

ajordanr@pharynx ~/m/b/c/c/l/s/t/k/v5.10 (ajordanr/clang-cherrypick)> git merge-base HEAD 0c3939b002530b0e7d7443652d38fffa875bccd1
024a4a45fdf87218e3c0925475b05a27bcea103f
ajordanr@pharynx ~/m/b/c/c/l/s/t/k/v5.10 (ajordanr/clang-cherrypick)> git merge-base HEAD 80ecbebebfe80ab4127ef0c23abb57b809248fcc
024a4a45fdf87218e3c0925475b05a27bcea103f

Will run a kernel build locally with these cherrypicked, and will close out this bug. Thank you for your dedication! We would likely have missed these patches on our end.

[ajordanr-google]

At a first pass of building the 5.10 kernel, we apparently are still encountering 3 other places where -mhard-float is being passed in the amd gpu driver code.

Running make directly with verbose gave the remaining three compile commands that pass it:

  x86_64-cros-linux-gnu-clang  -Wp,-MMD,drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/.dcn_calcs.o.d  -nostdinc -isystem /usr/lib64/clang/22/include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include -I./arch/x86/include/generated -I/mnt/host/source/src/third_party/kernel/v5.10/include -I./include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/mnt/host/source/src/third_party/kernel/v5.10/include/uapi -I./include/generated/uapi -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/kconfig.h -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/compiler_types.h -D__KERNEL__ -Qunused-arguments -fmacro-prefix-map=/mnt/host/source/src/third_party/kernel/v5.10/= -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Wno-format-security -std=gnu11 -fno-integrated-as -Werror=unknown-warning-option -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -fcf-protection=none -m64 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mstack-alignment=8 -mskip-rax-setup -mtune=generic -mno-red-zone -mcmodel=kernel -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -mfunction-return=thunk-extern -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-address-of-packed-member -O2 --param=allow-store-data-races=0 -Wframe-larger-than=2048 -fstack-protector-strong -Werror -Wno-format-invalid-specifier -Wno-gnu -mno-global-merge -Wno-unused-but-set-variable -Wno-unused-const-variable -ftrivial-auto-var-init=zero -g -gdwarf-4 -pg -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -fno-strict-overflow -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -fno-builtin-wcslen -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -Wno-unaligned-access -Wno-cast-function-type-strict -Wno-enum-compare-conditional -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu11 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu12 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/smumgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/hw -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/clk_mgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/freesync -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/color -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/info_packet -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/power -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dmub/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp -DBUILD_FEATURE_TIMING_SYNC=0 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdgpu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../acp/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdkfd -mhard-float -msse -msse2 -I /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu -I ./drivers/gpu/drm/amd/amdgpu    -DKBUILD_MODFILE='"drivers/gpu/drm/amd/amdgpu/amdgpu"' -DKBUILD_BASENAME='"dcn_calcs"' -DKBUILD_MODNAME='"amdgpu"' -c -o drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.o /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calcs.c
   ./tools/objtool/objtool orc generate  --no-fp --retpoline --rethunk --uaccess drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser_common.o
   if [ drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser_common.o != "scripts/mod/empty.o" ]; then ./scripts/recordmcount  "drivers/gpu/drm/amd/amdgpu/../display/dc/bios/bios_parser_common.o"; fi;
  x86_64-cros-linux-gnu-clang  -Wp,-MMD,drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/.dcn_calc_math.o.d  -nostdinc -isystem /usr/lib64/clang/22/include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include -I./arch/x86/include/generated -I/mnt/host/source/src/third_party/kernel/v5.10/include -I./include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/mnt/host/source/src/third_party/kernel/v5.10/include/uapi -I./include/generated/uapi -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/kconfig.h -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/compiler_types.h -D__KERNEL__ -Qunused-arguments -fmacro-prefix-map=/mnt/host/source/src/third_party/kernel/v5.10/= -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Wno-format-security -std=gnu11 -fno-integrated-as -Werror=unknown-warning-option -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -fcf-protection=none -m64 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mstack-alignment=8 -mskip-rax-setup -mtune=generic -mno-red-zone -mcmodel=kernel -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -mfunction-return=thunk-extern -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-address-of-packed-member -O2 --param=allow-store-data-races=0 -Wframe-larger-than=2048 -fstack-protector-strong -Werror -Wno-format-invalid-specifier -Wno-gnu -mno-global-merge -Wno-unused-but-set-variable -Wno-unused-const-variable -ftrivial-auto-var-init=zero -g -gdwarf-4 -pg -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -fno-strict-overflow -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -fno-builtin-wcslen -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -Wno-unaligned-access -Wno-cast-function-type-strict -Wno-enum-compare-conditional -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu11 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu12 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/smumgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/hw -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/clk_mgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/freesync -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/color -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/info_packet -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/power -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dmub/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp -DBUILD_FEATURE_TIMING_SYNC=0 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdgpu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../acp/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdkfd -mhard-float -msse -msse2 -Wno-tautological-compare -I /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu -I ./drivers/gpu/drm/amd/amdgpu    -DKBUILD_MODFILE='"drivers/gpu/drm/amd/amdgpu/amdgpu"' -DKBUILD_BASENAME='"dcn_calc_math"' -DKBUILD_MODNAME='"amdgpu"' -c -o drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calc_math.o /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calc_math.c
   ./tools/objtool/objtool orc generate  --no-fp --retpoline --rethunk --uaccess drivers/gpu/drm/amd/amdgpu/../display/dc/bios/command_table_helper2.o
   if [ drivers/gpu/drm/amd/amdgpu/../display/dc/bios/command_table_helper2.o != "scripts/mod/empty.o" ]; then ./scripts/recordmcount  "drivers/gpu/drm/amd/amdgpu/../display/dc/bios/command_table_helper2.o"; fi;
  x86_64-cros-linux-gnu-clang  -Wp,-MMD,drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/.dcn_calc_auto.o.d  -nostdinc -isystem /usr/lib64/clang/22/include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include -I./arch/x86/include/generated -I/mnt/host/source/src/third_party/kernel/v5.10/include -I./include -I/mnt/host/source/src/third_party/kernel/v5.10/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/mnt/host/source/src/third_party/kernel/v5.10/include/uapi -I./include/generated/uapi -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/kconfig.h -include /mnt/host/source/src/third_party/kernel/v5.10/include/linux/compiler_types.h -D__KERNEL__ -Qunused-arguments -fmacro-prefix-map=/mnt/host/source/src/third_party/kernel/v5.10/= -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Wno-format-security -std=gnu11 -fno-integrated-as -Werror=unknown-warning-option -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -fcf-protection=none -m64 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mstack-alignment=8 -mskip-rax-setup -mtune=generic -mno-red-zone -mcmodel=kernel -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -mfunction-return=thunk-extern -fno-delete-null-pointer-checks -Wno-frame-address -Wno-format-truncation -Wno-format-overflow -Wno-address-of-packed-member -O2 --param=allow-store-data-races=0 -Wframe-larger-than=2048 -fstack-protector-strong -Werror -Wno-format-invalid-specifier -Wno-gnu -mno-global-merge -Wno-unused-but-set-variable -Wno-unused-const-variable -ftrivial-auto-var-init=zero -g -gdwarf-4 -pg -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -fno-strict-overflow -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -fno-builtin-wcslen -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -Wno-unaligned-access -Wno-cast-function-type-strict -Wno-enum-compare-conditional -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu11 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu12 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu13 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/smumgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/ -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/inc/hw -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/clk_mgr -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/freesync -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/color -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/info_packet -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/power -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dmub/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/modules/hdcp -DBUILD_FEATURE_TIMING_SYNC=0 -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include/asic_reg -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdgpu -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../pm/inc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../acp/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/include -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm -I/mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../amdkfd -mhard-float -msse -msse2 -I /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu -I ./drivers/gpu/drm/amd/amdgpu    -DKBUILD_MODFILE='"drivers/gpu/drm/amd/amdgpu/amdgpu"' -DKBUILD_BASENAME='"dcn_calc_auto"' -DKBUILD_MODNAME='"amdgpu"' -c -o drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calc_auto.o /mnt/host/source/src/third_party/kernel/v5.10/drivers/gpu/drm/amd/amdgpu/../display/dc/calcs/dcn_calc_auto.c

I assume we're still missing a patch somewhere?

[nathanchance]

I assume we're still missing a patch somewhere?

It looks like these files were moved from drivers/gpu/drm/amd/display/dc/calcs to drivers/gpu/drm/amd/display/dc/dml in 5.18 (and it was later backported to 5.15), which means we would need

diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
index cb7c37ef8735..1b3e3926b706 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
@@ -26,7 +26,8 @@
 #

 ifdef CONFIG_X86
-calcs_ccflags := -mhard-float -msse
+calcs_ccflags-$(CONFIG_CC_IS_GCC) := -mhard-float
+calcs_ccflags := $(calcs_ccflags-y) -msse
 endif

 ifdef CONFIG_PPC64

in 5.10 as a standalone patch (basically doing the same thing as https://git.kernel.org/stable/c/0c3939b002530b0e7d7443652d38fffa875bccd1). We could try to apply the shuffle patch instead but that might have more conflicts or other issues.