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References: <202208221506.0Lo051G4-lkp@intel.com> <CACRpkdYoesPenQizTc6_MRZ14THBSFwyHb7oWJdR+CYYiJYYpQ@mail.gmail.com>
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From:   Doug Anderson <dianders@chromium.org>
Date:   Fri, 26 Aug 2022 08:48:42 -0700
Message-ID: <CAD=FV=Vxdoo21OQJ-Ad57-gFVcJ7biQipoJqDE2bSpLC2NxrhQ@mail.gmail.com>
Subject: Re: ld.lld: error: undefined symbol: drm_gem_fb_get_obj
To:     Linus Walleij <linus.walleij@linaro.org>
Cc:     kernel test robot <lkp@intel.com>, llvm@lists.linux.dev,
        kbuild-all@lists.01.org, LKML <linux-kernel@vger.kernel.org>,
        =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= <noralf@tronnes.org>
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Hi,

On Fri, Aug 26, 2022 at 1:26 AM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Mon, Aug 22, 2022 at 9:27 AM kernel test robot <lkp@intel.com> wrote:
>
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   1c23f9e627a7b412978b4e852793c5e3c3efc555
> > commit: 57f6190a60ecc19f1ddddac0d7ea6524229271a9 drm/panel: ws2401: Add driver for WideChips WS2401
> > date:   1 year, 1 month ago
> > config: x86_64-randconfig-a002-20220822 (https://download.01.org/0day-ci/archive/20220822/202208221506.0Lo051G4-lkp@intel.com/config)
> > compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
> > 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
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=57f6190a60ecc19f1ddddac0d7ea6524229271a9
> >         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout 57f6190a60ecc19f1ddddac0d7ea6524229271a9
> >         # save the config file
> >         mkdir build_dir && cp config build_dir/.config
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash
> >
> > If you fix the issue, kindly add following tag where applicable
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All errors (new ones prefixed by >>):
> >
> > >> ld.lld: error: undefined symbol: drm_gem_fb_get_obj
> >    >>> referenced by drm_mipi_dbi.c:203 (drivers/gpu/drm/drm_mipi_dbi.c:203)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
> >    >>> referenced by drm_mipi_dbi.c:258 (drivers/gpu/drm/drm_mipi_dbi.c:258)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_fb_dirty) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_fb_swab
> >    >>> referenced by drm_mipi_dbi.c:219 (drivers/gpu/drm/drm_mipi_dbi.c:219)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_atomic_helper_connector_destroy_state
> >    >>> referenced by drm_mipi_dbi.c
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_connector_funcs) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_gem_fb_create_with_dirty
> >    >>> referenced by drm_mipi_dbi.c
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_mode_config_funcs) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_atomic_helper_check
> >    >>> referenced by drm_mipi_dbi.c
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_mode_config_funcs) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_atomic_helper_commit
> >    >>> referenced by drm_mipi_dbi.c
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_mode_config_funcs) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_fb_xrgb8888_to_rgb565
> >    >>> referenced by drm_mipi_dbi.c:224 (drivers/gpu/drm/drm_mipi_dbi.c:224)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_fb_memcpy
> >    >>> referenced by drm_mipi_dbi.c:221 (drivers/gpu/drm/drm_mipi_dbi.c:221)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_buf_copy) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_atomic_helper_damage_merged
> >    >>> referenced by drm_mipi_dbi.c:318 (drivers/gpu/drm/drm_mipi_dbi.c:318)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_pipe_update) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_simple_display_pipe_init
> >    >>> referenced by drm_mipi_dbi.c:529 (drivers/gpu/drm/drm_mipi_dbi.c:529)
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_dev_init_with_formats) in archive drivers/built-in.a
> > --
> > >> ld.lld: error: undefined symbol: drm_atomic_helper_connector_reset
> >    >>> referenced by drm_mipi_dbi.c
> >    >>>               gpu/drm/drm_mipi_dbi.o:(mipi_dbi_connector_funcs) in archive drivers/built-in.a
>
> I don't understand this error report, please robot, analyze further and come
> back with details on what needs to be fixed.

I've never been accused of being a robot (OK, well, there was that one
time...), but I can probably still help a little...

I followed the "steps to reproduce" from the report and got the
failure. Basically the problem is this:

$ grep DRM_MIPI_DBI build_dir/.config
CONFIG_DRM_MIPI_DBI=y

$ grep DRM_KMS_HELPER build_dir/.config
CONFIG_DRM_KMS_HELPER=m

...so you're the MIPI DBI code is builtin and calling into the KMS
helper which is a module. That's does not compute. <ERR>. <ERR>.
<SHUTTING DOWN>.

Unfortunately, fixing the error isn't the most trivial thing in the
world. If you just do this:

 config DRM_MIPI_DBI
        tristate
+       select DRM_KMS_HELPER
        depends on DRM

...then you get a circular dependency:

drivers/gpu/drm/Kconfig:76:error: recursive dependency detected!
drivers/gpu/drm/Kconfig:76:     symbol DRM_KMS_HELPER is selected by
DRM_MIPI_DBI
drivers/gpu/drm/Kconfig:31:     symbol DRM_MIPI_DBI is selected by
DRM_PANEL_ILITEK_ILI9341
drivers/gpu/drm/panel/Kconfig:165:      symbol
DRM_PANEL_ILITEK_ILI9341 depends on DRM_KMS_HELPER
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"

...and if you do this:

 config DRM_MIPI_DBI
        tristate
        depends on DRM
+       depends on DRM_KMS_HELPER

...then you get errors like this:

WARNING: unmet direct dependencies detected for DRM_MIPI_DBI
  Depends on [m]: HAS_IOMEM [=y] && DRM [=y] && DRM_KMS_HELPER [=m]
  Selected by [y]:
  - DRM_PANEL_WIDECHIPS_WS2401 [=y] && HAS_IOMEM [=y] && DRM [=y] &&
DRM_PANEL [=y] && SPI [=y] && GPIOLIB [=y] && BACKLIGHT_CLASS_DEVICE
[=y]
  Selected by [m]:
  - TINYDRM_ILI9225 [=m] && HAS_IOMEM [=y] && DRM [=y] && SPI [=y]
  - TINYDRM_ILI9486 [=m] && HAS_IOMEM [=y] && DRM [=y] && SPI [=y]
  - TINYDRM_ST7586 [=m] && HAS_IOMEM [=y] && DRM [=y] && SPI [=y]
  - TINYDRM_ST7735R [=m] && HAS_IOMEM [=y] && DRM [=y] && SPI [=y]


Hopefully that at least explains the problem even if it doesn't
magically give a solution. ;-)

-Doug