Re: [PATCH] fbdev: make FB_BACKLIGHT a tristate

[Rob Clark]

On Thu, Oct 11, 2018 at 3:02 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Thu, Oct 11, 2018 at 3:16 AM Rob Clark <robdclark@xxxxxxxxx> wrote:
> >
> > On Wed, Oct 10, 2018 at 11:35 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > >
> > > On 10/10/18, Rob Clark <robdclark@xxxxxxxxx> wrote:
> > > > BACKLIGHT_CLASS_DEVICE is already tristate, but a dependency
> > > > FB_BACKLIGHT prevents it from being built as a module.  There
> > > > doesn't seem to be any particularly good reason for this, so
> > > > switch FB_BACKLIGHT over to tristate.
> > > >
> > > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxx>
> > >
> > > I don't see anything immediately wrong, but anything related to
> > > BACKLIGHT_CLASS_DEVICE, BACKLIGHT_LCD_SUPPORT
> > > and FB_BACKLIGHT is really fragile in Kconfig, because of the
> > > way those interact with other options.
> > >
> > > I've applied your patch to my randconfig build tree for testing,
> > > let's see what happens there before you apply it.
> > >
> >
> > thanks.. tbh the fragility of backlight vs kconfig is why I've
> > procrastinated on fixing this for a while.. in the end the solution
> > seems not as bad as I feared (and after a iteration or two makes rhel
> > kernel builds for various archs happy, at least).. but defn some
> > randconfig build testing is in order.
>
> Ok, my overnight testing shows no regression, so please add
>
> Tested-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks

>
> > PS. discovering that the thing you need to fix (a) never really worked
> > as intended, and (b) involves backlight + fbdev.. is never a good way
> > to start your day ;-)
>
> I still have a bunch of related fixes in my tree that address
> randconfig builds that never worked. I think at one point
> I got a few 'Reviewed-by' replies from DRM folks, but then
> nobody picked it up and subsequently it stopped applying.
> I need to go back and dig out all the dependent patches from
> my randconfig tree and resend that.

I assume those patches (and this one) would be picked up via fbdev tree?

BR,
-R