reproduce (this is a W=1 build):
        git remote add linux-nvme git://git.infradead.org/nvme.git
        git fetch --no-tags linux-nvme nvme-6.19
        git checkout 8d9937531a4d3cb6d2d352c46dd807bfa52988b6
        # apt-get install sparse
        # sparse version: v0.6.4-71-g610d841d

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/nvme/host/