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

From: Thomas Zimmermann
Date: Wed Feb 02 2022 - 10:54:13 EST


Hi

Am 02.02.22 um 16:37 schrieb Doug Anderson:
Hi,

On Wed, Feb 2, 2022 at 2:25 AM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote:

Hi

Am 02.02.22 um 10:28 schrieb Ard Biesheuvel:
On Wed, 2 Feb 2022 at 10:08, Thomas Zimmermann <tzimmermann@xxxxxxx> 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@xxxxxxxxxx>

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@xxxxxxxxxxxxx/

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

Yep, apparently this was broken before. We recently moved these symbols from CONFIG_DRM_KMS_HELPER behind CONFIG_DRM_DP_HELPER. We'd have to use that instead.

Best regards
Thomas


-Doug

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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