Re: [next] arm: panel-edp.c:(.text+0xb74): undefined reference to `drm_panel_dp_aux_backlight'

From: Doug Anderson <dianders@chromium.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Marek Vasut <marex@denx.de>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	regressions@lists.linux.dev, Arnd Bergmann <arnd@arndb.de>,
	Yunlong Jia <yunlong.jia@ecs.corp-partner.google.com>,
	David Airlie <airlied@linux.ie>,
	Naresh Kamboju <naresh.kamboju@linaro.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	open list <linux-kernel@vger.kernel.org>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Linux-Next Mailing List <linux-next@vger.kernel.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	lkft-triage@lists.linaro.org,
	Grace Mi <grace.mi@ecs.corp-partner.google.com>,
	Sam Ravnborg <sam@ravnborg.org>, Ard Biesheuvel <ardb@kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [next] arm: panel-edp.c:(.text+0xb74): undefined reference to `drm_panel_dp_aux_backlight'
Date: Wed, 2 Feb 2022 07:37:47 -0800	[thread overview]
Message-ID: <CAD=FV=UzVczyMKiCt9tkMBveGqWFbACMF_Z1GRWypz+awSO06Q@mail.gmail.com> (raw)
In-Reply-To: <a1dd9d31-3ad0-b58f-c67b-5896048281ed@suse.de>

Hi,

On Wed, Feb 2, 2022 at 2:25 AM Thomas Zimmermann <tzimmermann@suse.de> wrote:
>
> Hi
>
> Am 02.02.22 um 10:28 schrieb Ard Biesheuvel:
> > On Wed, 2 Feb 2022 at 10:08, Thomas Zimmermann <tzimmermann@suse.de> wrote:
> >>
> >> Hi
> >>
> >> Am 02.02.22 um 10:02 schrieb Naresh Kamboju:
> >>> Following builds failed on Linux next 20220202 arm architecture.
> >>>     - arm-gcc-10-omap2plus_defconfig
> >>>     - arm-clang-nightly-shmobile_defconfig
> >>>     - arm-gcc-8-lpc32xx_defconfig
> >>>     - arm-clang-13-shmobile_defconfig
> >>>     - arm-gcc-10-shmobile_defconfig
> >>>     - arm-clang-11-shmobile_defconfig
> >>>     - arm-clang-11-omap2plus_defconfig
> >>>     - arm-clang-13-omap2plus_defconfig
> >>>     - arm-clang-11-lpc32xx_defconfig
> >>>     - arm-gcc-8-omap2plus_defconfig
> >>>     - arm-gcc-9-vexpress_defconfig
> >>>     - arm-clang-nightly-lpc32xx_defconfig
> >>>     - arm-gcc-9-shmobile_defconfig
> >>>     - arm-clang-13-lpc32xx_defconfig
> >>>     - arm-gcc-10-sama5_defconfig
> >>>     - arm-clang-11-vexpress_defconfig
> >>>     - arm-clang-11-sama5_defconfig
> >>>     - arm-gcc-9-omap2plus_defconfig
> >>>     - arm-clang-nightly-sama5_defconfig
> >>>     - arm-clang-13-vexpress_defconfig
> >>>     - arm-clang-nightly-vexpress_defconfig
> >>>     - arm-gcc-9-lpc32xx_defconfig
> >>>     - arm-clang-12-vexpress_defconfig
> >>>     - arm-gcc-10-vexpress_defconfig
> >>>     - arm-clang-12-shmobile_defconfig
> >>>     - arm-gcc-11-omap2plus_defconfig
> >>>     - arm-gcc-9-sama5_defconfig
> >>>     - arm-gcc-8-shmobile_defconfig
> >>>     - arm-gcc-10-lpc32xx_defconfig
> >>>     - arm-clang-12-omap2plus_defconfig
> >>>     - arm-gcc-8-vexpress_defconfig
> >>>     - arm-clang-12-sama5_defconfig
> >>>     - arm-clang-nightly-omap2plus_defconfig
> >>>     - arm-gcc-11-lpc32xx_defconfig
> >>>     - arm-gcc-11-sama5_defconfig
> >>>     - arm-gcc-11-shmobile_defconfig
> >>>     - arm-gcc-11-vexpress_defconfig
> >>>     - arm-gcc-8-sama5_defconfig
> >>>     - arm-clang-13-sama5_defconfig
> >>>     - arm-clang-12-lpc32xx_defconfig
> >>>
> >>>
> >>> make --silent --keep-going --jobs=8  ARCH=arm
> >>> CROSS_COMPILE=arm-linux-gnueabihf- 'CC=sccache
> >>> arm-linux-gnueabihf-gcc' 'HOSTCC=sccache gcc' vexpress_defconfig
> >>> make --silent --keep-going --jobs=8  ARCH=arm
> >>> CROSS_COMPILE=arm-linux-gnueabihf- 'CC=sccache
> >>> arm-linux-gnueabihf-gcc' 'HOSTCC=sccache gcc'
> >>> arm-linux-gnueabihf-ld: drivers/gpu/drm/panel/panel-edp.o: in function
> >>> `panel_edp_probe':
> >>> panel-edp.c:(.text+0xb74): undefined reference to `drm_panel_dp_aux_backlight'
> >>> make[1]: *** [/builds/linux/Makefile:1222: vmlinux] Error 1
> >>>
> >>>
> >>> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> >>>
> >>> meta data:
> >>> -----------
> >>>       git describe: next-20220202
> >>>       git_repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> >>>       target_arch: arm
> >>>       kconfig: vexpress_defconfig
> >>>       toolchain: gcc-11
> >>>
> >>> Build log:
> >>> -------------
> >>> https://builds.tuxbuild.com/24XRim72vFXix6l6MdAJNENy6je/
> >>>
> >>> Steps to reproduce:
> >>> --------------------
> >>> # To install tuxmake on your system globally:
> >>> # sudo pip3 install -U tuxmake
> >>> #
> >>> # See https://docs.tuxmake.org/ for complete documentation.
> >>> # Original tuxmake command with fragments listed below.
> >>>
> >>> tuxmake --runtime podman --target-arch arm --toolchain gcc-11
> >>> --kconfig vexpress_defconfig
> >>>
> >>> tuxmake --runtime podman --target-arch arm --toolchain gcc-11
> >>> --kconfig https://builds.tuxbuild.com/24XRim72vFXix6l6MdAJNENy6je/config
> >>
> >> You'll now need
> >>
> >>     CONFIG_DRM_DP_HELPER=y
> >>
> >> in your config.
> >>
> >
> > That should never be the solution for linker errors such as this one.
> >
> > If CONFIG_DRM_PANEL_EDP relies on something provided by
> > CONFIG_DRM_DP_HELPER, it should select it or depend on it in Kconfig.
>
> Of course, we'll provide a patch for the Kconfig files.

There was discussion about this last November but I guess nothing came of it?

https://lore.kernel.org/r/20211117062704.14671-1-rdunlap@infradead.org/

In there Arnd provided a proposed patch. If everyone likes that and it
fixes things then we can apply it...

-Doug