Re: [linux-next:master 2224/7715] drivers/remoteproc/mtk_scp.c:755:37: warning: unused variable 'mt8183_of_data'

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Wed 25 Nov 09:24 CST 2020, Souptick Joarder wrote:

> On Tue, Nov 24, 2020 at 8:34 PM kernel test robot <lkp@intel.com> wrote:
> >
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head:   d9137320ac06f526fe3f9a3fdf07a3b14201068a
> > commit: b8ba904503311036dfeb758d81ef8d1be37cb8fc [2224/7715] remoteproc/mtk_scp: surround DT device IDs with CONFIG_OF
> > config: arm-randconfig-r003-20201124 (attached as .config)
> > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project df9ae5992889560a8f3c6760b54d5051b47c7bf5)
> > 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 arm cross compiling tool for clang build
> >         # apt-get install binutils-arm-linux-gnueabi
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=b8ba904503311036dfeb758d81ef8d1be37cb8fc
> >         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> >         git fetch --no-tags linux-next master
> >         git checkout b8ba904503311036dfeb758d81ef8d1be37cb8fc
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> drivers/remoteproc/mtk_scp.c:755:37: warning: unused variable 'mt8183_of_data' [-Wunused-const-variable]
> >    static const struct mtk_scp_of_data mt8183_of_data = {
> >                                        ^
> > >> drivers/remoteproc/mtk_scp.c:765:37: warning: unused variable 'mt8192_of_data' [-Wunused-const-variable]
> >    static const struct mtk_scp_of_data mt8192_of_data = {
> >                                        ^
> >    2 warnings generated.
> 
> These 2 variables are used when CONFIG_OF is defined and CONFIG_OF is
> not enabled
> in the attached config file.
> 
> So mt8183_of_data & mt8192_of_data need to move under CONFIG_OF.
> 
> I will post a patch.
> 

We had the same warning on mtk_scp_of_match last week and I merged
Alexandre's fix without giving it much thought. Extending the CONFIG_OF
guard to also cover the references mtk_scp_of_data would mean that we
now have 10 unused functions instead.

On the flip-side, there's no harm in just dropping the of_match_ptr()
wrapping of mtk_scp_of_match in the definition of mtk_scp_driver and we
avoid this whole problem.  We "waste" a little bit of memory in the
COMPILE_TEST case, but we get compile testing of those functions as
well.

Regards,
Bjorn

> 
> 
> >
> > vim +/mt8183_of_data +755 drivers/remoteproc/mtk_scp.c
> >
> > 63c13d61eafe460 Erin Lo      2019-11-12  754
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21 @755  static const struct mtk_scp_of_data mt8183_of_data = {
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  756    .scp_before_load = mt8183_scp_before_load,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  757    .scp_irq_handler = mt8183_scp_irq_handler,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  758    .scp_reset_assert = mt8183_scp_reset_assert,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  759    .scp_reset_deassert = mt8183_scp_reset_deassert,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  760    .scp_stop = mt8183_scp_stop,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  761    .host_to_scp_reg = MT8183_HOST_TO_SCP,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  762    .host_to_scp_int_bit = MT8183_HOST_IPC_INT_BIT,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  763  };
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  764
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21 @765  static const struct mtk_scp_of_data mt8192_of_data = {
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  766    .scp_before_load = mt8192_scp_before_load,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  767    .scp_irq_handler = mt8192_scp_irq_handler,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  768    .scp_reset_assert = mt8192_scp_reset_assert,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  769    .scp_reset_deassert = mt8192_scp_reset_deassert,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  770    .scp_stop = mt8192_scp_stop,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  771    .host_to_scp_reg = MT8192_GIPC_IN_SET,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  772    .host_to_scp_int_bit = MT8192_HOST_IPC_INT_BIT,
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  773  };
> > fd0b6c1ff85a489 Pi-Hsun Shih 2020-09-21  774
> >
> > :::::: The code at line 755 was first introduced by commit
> > :::::: fd0b6c1ff85a489bcf1bcf58af64da1aeffd39f0 remoteproc/mediatek: Add support for mt8192 SCP
> >
> > :::::: TO: Pi-Hsun Shih <pihsun@chromium.org>
> > :::::: CC: Bjorn Andersson <bjorn.andersson@linaro.org>
> >
> > ---
> > 0-DAY CI Kernel Test Service, Intel Corporation
> > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org