Re: [linux-next:master 2238/9385] drivers/gpu/drm/i915/display/intel_display_power.h:256:70: error: declaration of 'struct seq_file' will not be visible outside of this function

[Nick Desaulniers <ndesaulniers@google.com>]

On Wed, Jun 14, 2023 at 4:25 AM Christian Brauner <brauner@kernel.org> wrote:
>
> On Tue, Jun 13, 2023 at 10:39:01PM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head:   1f6ce8392d6ff486af5ca96df9ded5882c4b6977
> > commit: ef104443bffa004f631729dfc924f0b84abbd602 [2238/9385] procfs: consolidate arch_report_meminfo declaration
> > config: x86_64-randconfig-r036-20230612 (https://download.01.org/0day-ci/archive/20230613/202306132237.Z4LJE8bP-lkp@intel.com/config)
> > compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
> > reproduce (this is a W=1 build):
> >         mkdir -p ~/bin
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=ef104443bffa004f631729dfc924f0b84abbd602
> >         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 ef104443bffa004f631729dfc924f0b84abbd602
> >         # save the config file
> >         mkdir build_dir && cp config build_dir/.config
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202306132237.Z4LJE8bP-lkp@intel.com/
> >
> > All errors (new ones prefixed by >>):
> >
> >    In file included from <built-in>:4:
> >    In file included from drivers/gpu/drm/i915/display/intel_display_power_well.h:10:
> > >> drivers/gpu/drm/i915/display/intel_display_power.h:256:70: error: declaration of 'struct seq_file' will not be visible outside of this function [-Werror,-Wvisibility]
> >    void intel_display_power_debug(struct drm_i915_private *i915, struct seq_file *m);
>
> This seems odd. Arnd, any idea?

-Wvisibility is usually the result of a missed header inclusion.
Since the parameter `i915` is a pointer to a type that hasn't been
declared yet, it's an opaque type.  The code can compile just fine if
the members are not accessed, but this is usually a code smell of
someone using a type without the correct #include or forward
declaration.

I see lots of forward declaration of `struct drm_i915_private` in
headers under drivers/gpu/drm/i915/, but maybe
drivers/gpu/drm/i915/display/intel_display_power_well.h is missing
one?

commit ef1e17089190 ("drm/i915: Move power well get/put/enable/disable
functions to a n

seems to have added it though...
-- 
Thanks,
~Nick Desaulniers