From: Randy Dunlap <rdunlap@infradead.org>
To: Gustavo Padovan <gus@collabora.com>
Cc: kernelci <kernelci@lists.linux.dev>,
kernelci-results <kernelci-results@groups.io>,
"Guido Günther" <agx@sigxcpu.org>,
"Neil Armstrong" <neil.armstrong@linaro.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
phone-devel <phone-devel@vger.kernel.org>,
regressions <regressions@lists.linux.dev>,
linux-next <linux-next@vger.kernel.org>
Subject: Re: [REGRESSION] next/master: (build) undefined reference to `devm_backlight_device_register' in vmlinux...
Date: Fri, 17 Oct 2025 16:23:46 -0700 [thread overview]
Message-ID: <022e9853-6973-4000-940f-12f3bf68b50d@infradead.org> (raw)
In-Reply-To: <199ec75cce1.3f69ac7c921986.1695662047481478034@collabora.com>
On 10/16/25 2:59 AM, Gustavo Padovan wrote:
> Hi Randy,
>
>
> ---- On Thu, 16 Oct 2025 00:47:35 -0300 Randy Dunlap <rdunlap@infradead.org> wrote ---
>
> > Guido,
> >
> > Looks like this driver needs
> >
> > + depends on BACKLIGHT_CLASS_DEVICE
> >
> > to fix the build.
> >
> > @Gus- please read comments near bottom/end.
> >
> >
> > On 10/14/25 6:59 AM, KernelCI bot wrote:
> > >
> > >
> > >
> > >
> > > Hello,
> > >
> > > New build issue found on next/master:
> > >
> > > ---
> > > undefined reference to `devm_backlight_device_register' in vmlinux.unstripped (drivers/gpu/drm/panel/panel-visionox-rm69299.c) [logspec:kbuild,kbuild.compiler.linker_error]
> > > ---
> > >
> > > - dashboard: https://d.kernelci.org/i/maestro:c1e01dcc5d8b9be9ec47f44bbdb346c2464c0f02
> > > - giturl: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > > - commit HEAD: 13863a59e410cab46d26751941980dc8f088b9b3
> > > - tags: next-20251014
> > >
> > >
> > > Log excerpt:
> > > =====================================================
> > > LD .tmp_vmlinux1
> > > aarch64-linux-gnu-ld: Unexpected GOT/PLT entries detected!
> > > aarch64-linux-gnu-ld: Unexpected run-time procedure linkages detected!
> > > aarch64-linux-gnu-ld: drivers/gpu/drm/panel/panel-visionox-rm69299.o: in function `visionox_rm69299_create_backlight':
> > > /tmp/kci/linux/drivers/gpu/drm/panel/panel-visionox-rm69299.c:343: undefined reference to `devm_backlight_device_register'
> > >
> > > =====================================================
> > >
> > >
> > > # Builds where the incident occurred:
> > >
> > > ## defconfig+arm64-chromebook+CONFIG_ARM64_16K_PAGES=y on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-16k_pages-68ee4f14a6dc7c71db9fda21/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f14a6dc7c71db9fda21
> > >
> > > ## defconfig+arm64-chromebook+CONFIG_ARM64_64K_PAGES=y on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-64k_pages-68ee4f17a6dc7c71db9fda24/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f17a6dc7c71db9fda24
> > >
> > > ## defconfig+arm64-chromebook+CONFIG_CPU_BIG_ENDIAN=y+debug+kselftest+tinyconfig on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-mainline-big_endian-68ee4f32a6dc7c71db9fda39/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f32a6dc7c71db9fda39
> > >
> > > ## defconfig+arm64-chromebook+CONFIG_RANDOMIZE_BASE=y on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-randomize-68ee4f1fa6dc7c71db9fda2a/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f1fa6dc7c71db9fda2a
> > >
> > > ## defconfig+arm64-chromebook+kcidebug+lab-setup on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-chromebook-kcidebug-68ee4f2ba6dc7c71db9fda33/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f2ba6dc7c71db9fda33
> > >
> > > ## defconfig+arm64-chromebook+kselftest on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-kselftest-16k_pages-68ee4f23a6dc7c71db9fda2d/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f23a6dc7c71db9fda2d
> > >
> > > ## defconfig+arm64-chromebook+preempt_rt on (arm64):
> > > - compiler: gcc-12
> > > - config: https://files.kernelci.org/kbuild-gcc-12-arm64-preempt_rt_chromebook-68ee4f3aa6dc7c71db9fda3f/.config
> > > - dashboard: https://d.kernelci.org/build/maestro:68ee4f3aa6dc7c71db9fda3f
> > >
> > >
> > > #kernelci issue maestro:c1e01dcc5d8b9be9ec47f44bbdb346c2464c0f02
> > >
> > > Reported-by: kernelci.org bot <bot@kernelci.org>
> > >
> > > --
> > > This is an experimental report format. Please send feedback in!
> > > Talk to us at kernelci@lists.linux.dev
> > >
> > > Made with love by the KernelCI team - https://kernelci.org
> > >
> >
> > Gus, the CI reporter needs to learn how to do a few things because developers
> > (other than me ?) don't scrounge mailing lists to look for problems.
>
> Absolutely. Our goal is to automate as many steps as possible!
>
> > a. find the commit that caused the problem (or the email series)
> >
> > b. send the report (Cc:) to whoever wrote the patch and to the
> > appropriate mailing list.
> >
> > I expect that b. is easier than a., so do it first.
>
> b. is easier that a. yes, but I don't think we can do it first because we
> need to figure the patch first. Essentially, you are asking us for
> build bisections. Something that is already on our roadmap, but
> we didn't had the time to tackle yet, but should come to it in the
> coming months.
Sometimes a bisect could be required. For cases such as this report,
a simple git blame or git log will show the culprit. Although coding
that is not as simple as a human looking at the screen.
> >
> > And I'm sure that I have missed a thing or two that could be
> > added as well.
>
> Please keep the feedback coming!
--
~Randy
prev parent reply other threads:[~2025-10-17 23:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <176045034384.1788.868853922191153052@15dd6324cc71>
2025-10-16 3:47 ` [REGRESSION] next/master: (build) undefined reference to `devm_backlight_device_register' in vmlinux Randy Dunlap
2025-10-16 9:59 ` Gustavo Padovan
2025-10-17 23:23 ` Randy Dunlap [this message]
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