From: Jani Nikula <jani.nikula@linux.intel.com>
To: Wang Jinchao <wangjinchao@xfusion.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, stone.xulei@xfusion.com
Subject: Re: [PATCH] drm/i915: Fix Kconfig error for CONFIG_DRM_I915
Date: Mon, 14 Aug 2023 15:13:32 +0300 [thread overview]
Message-ID: <87h6p1ddoz.fsf@intel.com> (raw)
In-Reply-To: <ZNoY9bnpLlUwY8ai@fedora>
On Mon, 14 Aug 2023, Wang Jinchao <wangjinchao@xfusion.com> wrote:
> On Mon, Aug 14, 2023 at 10:26:45AM +0300, Jani Nikula wrote:
>> On Sat, 12 Aug 2023, Wang Jinchao <wangjinchao@xfusion.com> wrote:
>> > When CONFIG_DRM_I915 is set to 'y' and CONFIG_BACKLIGHT_CLASS_DEVICE
>> > is set to 'm', we encountered an ld.lld error during the build process:
>> >
>> > ld.lld: error: undefined symbol: backlight_device_get_by_name
>> > >>> referenced by intel_backlight.c:955
>> > >>> vmlinux.o:(intel_backlight_device_register)
>> >
>> > ld.lld: error: undefined symbol: backlight_device_register
>> > >>> referenced by intel_backlight.c:971
>> > >>> vmlinux.o:(intel_backlight_device_register)
>> >
>> > ld.lld: error: undefined symbol: backlight_device_unregister
>> > >>> referenced by intel_backlight.c:999
>> > >>> vmlinux.o:(intel_backlight_device_unregister)
>> >
>> > This issue occurred because intel_backlight_device_register and
>> > intel_backlight_device_unregister were enclosed within
>> > However, according to Kconfig, CONFIG_DRM_I915 will select
>> > BACKLIGHT_CLASS_DEVICE only if ACPI is enabled.
>> > This led to an error, which can be resolved by removing the
>> > conditional statements related to ACPI.
>>
>> The real fix is to use
>>
>> depends on BACKLIGHT_CLASS_DEVICE || BACKLIGHT_CLASS_DEVICE=n
> it works.
>>
>> but in order to do that, you need to change a lot of places to depend
> Why, what are the other places?
Generally when you have a mixture of depends on and select on a kconfig
symbol, you'll eventually end up with dependency problems.
BR,
Jani.
>> on, not select BACKLIGHT_CLASS_DEVICE, because otherwise you end up with
> got it.
>> other dependency issues.
>>
>> BR,
>> Jani.
>>
>> >
>> > Signed-off-by: Wang Jinchao <wangjinchao@xfusion.com>
>> > ---
>> > drivers/gpu/drm/i915/Kconfig | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
>> > index 01b5a8272a27..5003de921bf7 100644
>> > --- a/drivers/gpu/drm/i915/Kconfig
>> > +++ b/drivers/gpu/drm/i915/Kconfig
>> > @@ -24,7 +24,7 @@ config DRM_I915
>> > select IRQ_WORK
>> > # i915 depends on ACPI_VIDEO when ACPI is enabled
>> > # but for select to work, need to select ACPI_VIDEO's dependencies, ick
>> > - select BACKLIGHT_CLASS_DEVICE if ACPI
>> > + select BACKLIGHT_CLASS_DEVICE
>> > select INPUT if ACPI
>> > select X86_PLATFORM_DEVICES if ACPI
>> > select ACPI_WMI if ACPI
>>
>> --
>> Jani Nikula, Intel Open Source Graphics Center
--
Jani Nikula, Intel Open Source Graphics Center
next prev parent reply other threads:[~2023-08-14 12:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-12 9:19 [PATCH] drm/i915: Fix Kconfig error for CONFIG_DRM_I915 Wang Jinchao
2023-08-12 9:39 ` [PATCH v2] " Wang Jinchao
2023-08-14 7:26 ` [PATCH] " Jani Nikula
2023-08-14 12:07 ` Wang Jinchao
2023-08-14 12:13 ` Jani Nikula [this message]
2023-08-14 13:07 ` Wang Jinchao
2023-08-15 1:27 ` Wang Jinchao
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