reproduce (this is a W=1 build): git checkout 78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8 b4 shazam https://lore.kernel.org/r/20241220-acpm-v4-upstream-mbox-v6-3-a6942806e52a@linaro.org # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/mailbox/