On 2021-07-23 3:14 p.m., Cornij, Nikola wrote: > [AMD Official Use Only] > > +Harry > > -----Original Message----- > From: Daniel Vetter <dan...@ffwll.ch> > Sent: Friday, July 23, 2021 11:23 AM > To: Arnd Bergmann <a...@kernel.org> > Cc: Daniel Vetter <dan...@ffwll.ch>; Ben Skeggs <bske...@redhat.com>; David > Airlie <airl...@linux.ie>; Lyude Paul <ly...@redhat.com>; Arnd Bergmann > <a...@arndb.de>; Ville Syrjälä <ville.syrj...@linux.intel.com>; Cornij, > Nikola <nikola.cor...@amd.com>; dri-devel <dri-de...@lists.freedesktop.org>; > Nouveau Dev <nouveau@lists.freedesktop.org>; Linux Kernel Mailing List > <linux-ker...@vger.kernel.org> > Subject: Re: [PATCH] drm/nouveau/kms/nv50-: fix build failure with > CONFIG_BACKLIGHT=n > > On Fri, Jul 23, 2021 at 12:16:31PM +0200, Arnd Bergmann wrote: >> On Fri, Jul 23, 2021 at 11:25 AM Daniel Vetter <dan...@ffwll.ch> wrote: >>> >>> On Fri, Jul 23, 2021 at 11:15 AM Arnd Bergmann <a...@kernel.org> wrote: >>>> >>>> From: Arnd Bergmann <a...@arndb.de> >>>> >>>> When the backlight support is disabled, the driver fails to build: >>>> >>>> drivers/gpu/drm/nouveau/dispnv50/disp.c: In function >>>> 'nv50_sor_atomic_disable': >>>> drivers/gpu/drm/nouveau/dispnv50/disp.c:1665:59: error: 'struct >>>> nouveau_connector' has no member named 'backlight' >>>> 1665 | struct nouveau_backlight *backlight = >>>> nv_connector->backlight; >>>> | ^~ >>>> drivers/gpu/drm/nouveau/dispnv50/disp.c:1670:35: error: invalid use of >>>> undefined type 'struct nouveau_backlight' >>>> 1670 | if (backlight && backlight->uses_dpcd) { >>>> | ^~ >>>> drivers/gpu/drm/nouveau/dispnv50/disp.c:1671:64: error: invalid use of >>>> undefined type 'struct nouveau_backlight' >>>> 1671 | ret = drm_edp_backlight_disable(aux, >>>> &backlight->edp_info); >>>> | ^~ >>>> >>>> The patch that introduced the problem already contains some #ifdef >>>> checks, so just add another one that makes it build again. >>>> >>>> Fixes: 6eca310e8924 ("drm/nouveau/kms/nv50-: Add basic DPCD >>>> backlight support for nouveau") >>>> Signed-off-by: Arnd Bergmann <a...@arndb.de> >>> >>> Can we just toss the idea that BACKTLIGHT=n is a reasonable config >>> for drm drivers using backlights, and add depends BACKLIGHT to all >>> of them? >>> >>> I mean this is a perfect source of continued patch streams to keep >>> us all busy, but beyond that I really don't see the point ... I >>> frankly have better things to do, and especially with the big >>> drivers we have making backlight optional saves comparitively nothing. >>> -Daniel >> >> Yes! I'd definitely be in favor of that, I've wasted way too much time >> trying to sort through dependency loops and other problems with backlight >> support. >> >> Maybe we should leave the drivers/video/fbdev/ drivers untouched in >> this regard, at least for the moment, but for the drivers/gpu/drm >> users of backlight that would be a nice simplification, and even the >> smallest ones are unlikely to be used on systems that are too memory >> constrained to deal with 4KB extra .text. > > Yeah I think we can do this entirely ad-hoc, i.e. any time the backlight > wheel wobbles off again we nail it down for good for that driver with a > depends on BACKGLIGHT and remove any lingering #ifdef all over. > > If you want maybe start out with the biggest drm drivers in a series, I think > if nouveau/amdgpu/i915 folks ack this you're good to go to just convert as > things get in the way.
Sounds like a good idea to me. Harry > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch/>> _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/nouveau