Re: drivers/gpu/drm/kmb/kmb_dsi.c:812:2: warning: unused function 'set_test_mode_src_osc_freq_target_low_bits'

From: Nathan Chancellor
Date: Tue Sep 28 2021 - 12:43:38 EST


Hi Geert,

On Tue, Sep 28, 2021 at 05:39:19PM +0200, Geert Uytterhoeven wrote:
> On Tue, Sep 28, 2021 at 5:09 PM kernel test robot <lkp@xxxxxxxxx> wrote:
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head: 0513e464f9007b70b96740271a948ca5ab6e7dd7
> > commit: ade896460e4a62f5e4a892a98d254937f6f5b64c drm: DRM_KMB_DISPLAY should depend on ARCH_KEEMBAY
> > date: 11 months ago
> > config: mips-randconfig-r013-20210928 (attached as .config)
> > compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project dc6e8dfdfe7efecfda318d43a06fae18b40eb498)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install mips cross compiling tool for clang build
> > # apt-get install binutils-mips-linux-gnu
> > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ade896460e4a62f5e4a892a98d254937f6f5b64c
> > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > git fetch --no-tags linus master
> > git checkout ade896460e4a62f5e4a892a98d254937f6f5b64c
> > # save the attached .config to linux build tree
> > mkdir build_dir
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/gpu/drm/kmb/ drivers/net/ethernet/mellanox/mlxsw/ mm/
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> drivers/gpu/drm/kmb/kmb_dsi.c:812:2: warning: unused function 'set_test_mode_src_osc_freq_target_low_bits'
> > set_test_mode_src_osc_freq_target_low_bits(struct kmb_dsi
> > ^
> > >> drivers/gpu/drm/kmb/kmb_dsi.c:824:2: warning: unused function 'set_test_mode_src_osc_freq_target_hi_bits'
> > set_test_mode_src_osc_freq_target_hi_bits(struct kmb_dsi
>
> These two functions are "static inline", so there should not be such
> warning. Toolchain issue?

No toolchain issue, Masahiro specifically made clang W=1 builds warns on
static inline unused functions because of instances like this, see
commit 6863f5643dd7 ("kbuild: allow Clang to find unused static inline
functions for W=1 build").

Cheers,
Nathan