Re: [PATCH] nouveau: make backlight support non optional

From: Arnd Bergmann <arnd@kernel.org>
To: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Karol Herbst <kherbst@redhat.com>,
	ML nouveau <nouveau@lists.freedesktop.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Ben Skeggs <bskeggs@redhat.com>
Subject: Re: [PATCH] nouveau: make backlight support non optional
Date: Mon, 9 Aug 2021 15:30:38 +0200	[thread overview]
Message-ID: <CAK8P3a30acg_FX9iHqftKeVmS=L81bqYw3XMQJ8=1fP5aU7jMQ@mail.gmail.com> (raw)
In-Reply-To: <87tujyoitk.fsf@intel.com>

On Mon, Aug 9, 2021 at 3:20 PM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Sat, 24 Jul 2021, Arnd Bergmann <arnd@kernel.org> wrote:
> > On Sat, Jul 24, 2021 at 4:14 PM Karol Herbst <kherbst@redhat.com> wrote:
> >>
> >> we use the MXM_WMI in code. We also have to keep arm in mind and not
> >> break stuff there. So I will try to play around with your changes and
> >> see how that goes.
> >
> > Ok, should find any randconfig build failures for arm, arm64 or x86 over the
> > weekend. I also this on linux-next today
> >
> > ld: drivers/gpu/drm/i915/display/intel_panel.o: in function
> > `intel_backlight_device_register':
> > intel_panel.c:(.text+0x2804): undefined reference to `backlight_device_register'
> > ld: intel_panel.c:(.text+0x284e): undefined reference to
> > `backlight_device_register'
> > ld: drivers/gpu/drm/i915/display/intel_panel.o: in function
> > `intel_backlight_device_unregister':
> > intel_panel.c:(.text+0x28b1): undefined reference to
> > `backlight_device_unregister'
> >
> > and I added this same thing there to see how it goes:
>
> Last I checked (and it was a while a go) you really had to make all
> users of BACKLIGHT_CLASS_DEVICE depend not select it, otherwise you end
> up with recursive dependencies.

Yes, that is correct. It turns out that my randconfig tree already had a local
patch to change most of the other users (everything outside of drivers/gpu)
to 'depends on'.

      Arnd