reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git/commit/?id=88e76b926b193764694367e3411d004d5db78ccb
        git remote add superm1 https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git
        git fetch --no-tags superm1 superm1/brightness-changes-6.15
        git checkout 88e76b926b193764694367e3411d004d5db78ccb
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/