On 10/26/21 11:21 AM, Thomas Zimmermann wrote:
Hi
Am 25.10.21 um 14:13 schrieb Naresh Kamboju:
Regression found on arm gcc-11 built with multi_v5_defconfig Following build warnings / errors reported on linux next 20211025.
metadata: git_describe: next-20211025 git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git_short_log: 9ae1fbdeabd3 ("Add linux-next specific files for 20211025") target_arch: arm toolchain: gcc-11 config: multi_v5_defconfig
build error :
arm-linux-gnueabihf-ld: drivers/gpu/drm/drm_fb_cma_helper.o: in function `drm_fb_cma_get_gem_obj': drivers/gpu/drm/drm_fb_cma_helper.c:46: undefined reference to `drm_gem_fb_get_obj' arm-linux-gnueabihf-ld: drivers/gpu/drm/drm_fb_cma_helper.c:46: undefined reference to `drm_gem_fb_get_obj' arm-linux-gnueabihf-ld: drivers/gpu/drm/drm_fb_cma_helper.c:46: undefined reference to `drm_gem_fb_get_obj' arm-linux-gnueabihf-ld: drivers/gpu/drm/drm_fb_cma_helper.o: in function `drm_fb_cma_sync_non_coherent': drivers/gpu/drm/drm_fb_cma_helper.c:133: undefined reference to `drm_atomic_helper_damage_iter_init' arm-linux-gnueabihf-ld: drivers/gpu/drm/drm_fb_cma_helper.c:135: undefined reference to `drm_atomic_helper_damage_iter_next' make[1]: *** [Makefile:1252: vmlinux] Error 1 make[1]: Target '__all' not remade because of errors. make: *** [Makefile:226: __sub-make] Error 2
Reported-by: Linux Kernel Functional Testing lkft@linaro.org
build link:
https://builds.tuxbuild.com/1zzgFZBGjpQ5R0lawQFW9iJ39Hp/build.log
build config:
https://builds.tuxbuild.com/1zzgFZBGjpQ5R0lawQFW9iJ39Hp/config
Looking at this config, there is:
CONFIG_DRM=y # CONFIG_DRM_DP_AUX_CHARDEV is not set # CONFIG_DRM_DEBUG_MM is not set # CONFIG_DRM_DEBUG_SELFTEST is not set CONFIG_DRM_KMS_HELPER=m # CONFIG_DRM_LOAD_EDID_FIRMWARE is not set # CONFIG_DRM_DP_CEC is not set CONFIG_DRM_GEM_CMA_HELPER=y CONFIG_DRM_KMS_CMA_HELPER=y
GEM_CMA_HELPER depends on KMS_HELPER, but the latter is a module. That's probably the cause of the problem. Is it intentionally set this way?
The only drivers that select DRM_KMS_HELPER are both =m, so that's how DRM_KMS_HELPER is set also.
Symbol: DRM_KMS_HELPER [=m] Type : tristate Defined at drivers/gpu/drm/Kconfig:82 Depends on: HAS_IOMEM [=y] && DRM [=y] Selected by [m]: - DRM_ATMEL_HLCDC [=m] && HAS_IOMEM [=y] && DRM [=y] && OF [=y] && COMMON_CLK [=y] && MFD_ATMEL_HLCDC [=y] && ARM [=y] - DRM_ASPEED_GFX [=m] && HAS_IOMEM [=y] && DRM [=y] && OF [=y] && (COMPILE_TEST [=n] || ARCH_ASPEED [=y]) && MMU [=y]
I did the ARM cross-build and also see the linker error. I didn't understand why -- and still don't, but here is a little speculation:
In the past (e.g. 10 years ago), we have to move some .o files in lib/ from lib-y to obj-y so that they would always be included in the final object file and not cause their user/caller object files to suffer from undefined references. These happened because unused functions(?) in lib-y files are stripped out of the final object files. The same thing could be happening here (still just guessing).
Does that help any? I dunno.
Adding Arnd to Cc: to see if he has any ideas...
# To install tuxmake on your system globally # sudo pip3 install -U tuxmake tuxmake --runtime podman --target-arch arm --toolchain gcc-11 --kconfig multi_v5_defconfig
-- Linaro LKFT https://lkft.linaro.org