linux: master: x86_64: gcc-8: error: call to '__compiletime_assert_909' declared with attribute error: clamp() low limit dsc_min_bpc * 3 greater than high limit dsc_max_bpc * 3
The x86_64 and i386 build failed with defconfig with gcc-8 toolchain due to following build warnings / errors on the Torvalds Linux master branch. But gcc-13 builds pass.
First seen on v6.13-9485-g72deda0abee6 on Jan. 27, 2025 Good: v6.13-7644-gc2da8b3f914f on Jan. 27, 2025 Bad: v6.13-8265-g9c5968db9e62 on Jan. 27, 2025
i386: build: * gcc-8-i386_defconfig
x86_64: build: * gcc-8-x86_64_defconfig
Reported-by: Linux Kernel Functional Testing
Build log: --- make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build ARCH=x86_64 SRCARCH=x86 CROSS_COMPILE=x86_64-linux-gnu- 'CC=sccache x86_64-linux-gnu-gcc' 'HOSTCC=sccache gcc' In file included from <command-line>: In function 'intel_dp_dsc_compute_pipe_bpp_limits.isra.80', inlined from 'intel_dp_compute_config_limits' at drivers/gpu/drm/i915/display/intel_dp.c:2547:3: include/linux/compiler_types.h:542:38: error: call to '__compiletime_assert_909' declared with attribute error: clamp() low limit dsc_min_bpc * 3 greater than high limit dsc_max_bpc * 3 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ include/linux/compiler_types.h:523:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^~~~~~ include/linux/compiler_types.h:542:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^~~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^~~~~~~~~~~~~~~~~~ include/linux/minmax.h:188:2: note: in expansion of macro 'BUILD_BUG_ON_MSG' BUILD_BUG_ON_MSG(statically_true(ulo > uhi), \ ^~~~~~~~~~~~~~~~ include/linux/minmax.h:195:2: note: in expansion of macro '__clamp_once' __clamp_once(type, val, lo, hi, __UNIQUE_ID(v_), __UNIQUE_ID(l_), __UNIQUE_ID(h_)) ^~~~~~~~~~~~ include/linux/minmax.h:206:28: note: in expansion of macro '__careful_clamp' #define clamp(val, lo, hi) __careful_clamp(__auto_type, val, lo, hi) ^~~~~~~~~~~~~~~ drivers/gpu/drm/i915/display/intel_dp.c:2506:25: note: in expansion of macro 'clamp' limits->pipe.max_bpp = clamp(limits->pipe.max_bpp, dsc_min_bpc * 3, dsc_max_bpc * 3); ^~~~~ make[7]: *** [scripts/Makefile.build:194: drivers/gpu/drm/i915/display/intel_dp.o] Error 1
Links: --- build log: https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.13-9485-g7... details: https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.13-9485-g7... history: https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v6.13-9485-g7...
Steps to reproduce: ------------ $ tuxmake --runtime podman --target-arch x86_64 --toolchain gcc-8 --kconfig x86_64_defconfig
metadata: --- git describe: v6.13-9485-g72deda0abee6 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git sha: 72deda0abee6e705ae71a93f69f55e33be5bca5c kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/2sKEcVft7ytiSSvOSnAuA... build url: https://storage.tuxsuite.com/public/linaro/lkft/builds/2sKEcVft7ytiSSvOSnAuA... toolchain: gcc8 config: gcc-8-defconfig arch: i386 and x86_64
-- Linaro LKFT https://lkft.linaro.org
On Thu, 30 Jan 2025 15:01:21 +0530 Naresh Kamboju naresh.kamboju@linaro.org wrote:
The x86_64 and i386 build failed with defconfig with gcc-8 toolchain due to following build warnings / errors on the Torvalds Linux master branch. But gcc-13 builds pass.
First seen on v6.13-9485-g72deda0abee6 on Jan. 27, 2025 Good: v6.13-7644-gc2da8b3f914f on Jan. 27, 2025 Bad: v6.13-8265-g9c5968db9e62 on Jan. 27, 2025
i386: build: * gcc-8-i386_defconfig
x86_64: build: * gcc-8-x86_64_defconfig
Reported-by: Linux Kernel Functional Testing
Build log:
make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/build ARCH=x86_64 SRCARCH=x86 CROSS_COMPILE=x86_64-linux-gnu- 'CC=sccache x86_64-linux-gnu-gcc' 'HOSTCC=sccache gcc' In file included from <command-line>: In function 'intel_dp_dsc_compute_pipe_bpp_limits.isra.80', inlined from 'intel_dp_compute_config_limits' at drivers/gpu/drm/i915/display/intel_dp.c:2547:3: include/linux/compiler_types.h:542:38: error: call to '__compiletime_assert_909' declared with attribute error: clamp() low limit dsc_min_bpc * 3 greater than high limit dsc_max_bpc * 3
...
drivers/gpu/drm/i915/display/intel_dp.c:2506:25: note: in expansion of macro 'clamp' limits->pipe.max_bpp = clamp(limits->pipe.max_bpp, dsc_min_bpc * 3, dsc_max_bpc * 3);
The code is:
static void intel_dp_dsc_compute_pipe_bpp_limits(struct intel_dp *intel_dp, struct link_config_limits *limits) { struct intel_display *display = to_intel_display(intel_dp); int dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(); int dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(display);
limits->pipe.max_bpp = clamp(limits->pipe.max_bpp, dsc_min_bpc * 3, dsc_max_bpc * 3); limits->pipe.min_bpp = clamp(limits->pipe.min_bpp, dsc_min_bpc * 3, dsc_max_bpc * 3); }
with:
int intel_dp_dsc_min_src_input_bpc(void) { /* Min DSC Input BPC for ICL+ is 8 */ return 8; }
int intel_dp_dsc_max_src_input_bpc(struct intel_display *display) { /* Max DSC Input BPC for ICL is 10 and for TGL+ is 12 */ if (DISPLAY_VER(display) >= 12) return 12; if (DISPLAY_VER(display) == 11) return 10;
return 0; }
Although the little functions aren't static the compiler can assume that the local versions will be called and inline them.
It can then move the clamp() code into the conditionals in intel_dp_dsc_max_src_input_bpc() It then sees clamp(limit->pipe.max_bpp, 24, 0) and quite rightly complains.
Broken by 160672b86b0dd
David
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David Laight -
Naresh Kamboju