Re: [PATCH] drm: fix up fbdev Kconfig defaults

[Geert Uytterhoeven]

Hi Javier,

On Tue, Sep 12, 2023 at 9:48 AM Javier Martinez Canillas
<javierm@xxxxxxxxxx> wrote:
> Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> writes:
> > On Mon, Sep 11, 2023 at 10:53 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> [...]
>
> >> --- a/drivers/gpu/drm/Kconfig
> >> +++ b/drivers/gpu/drm/Kconfig
> >> @@ -135,7 +135,7 @@ config DRM_FBDEV_EMULATION
> >>         bool "Enable legacy fbdev support for your modesetting driver"
> >>         depends on DRM
> >>         select FRAMEBUFFER_CONSOLE_DETECT_PRIMARY if FRAMEBUFFER_CONSOLE
> >> -       default y
> >> +       default FB
> >
> > While this is true for existing configs, it is no longer true in general,
> > as DRM_FBDEV_EMULATION is no longer related to FB.
>
> Maybe default y if (FB_DEVICE || FRAMEBUFFER_CONSOLE) ?

Which is almost if FB_CORE? ;-)

Won't a dependency on FRAMEBUFFER_CONSOLE here introduce
a circular dependency, when combined with the hunk below?

> >>         help
> >>           Choose this option if you have a need for the legacy fbdev
> >>           support. Note that this support also provides the linux console
> >> diff --git a/drivers/video/console/Kconfig b/drivers/video/console/Kconfig
> >> index b575cf54174af..83c2d7329ca58 100644
> >> --- a/drivers/video/console/Kconfig
> >> +++ b/drivers/video/console/Kconfig
> >> @@ -74,6 +74,7 @@ config DUMMY_CONSOLE_ROWS
> >>  config FRAMEBUFFER_CONSOLE
> >>         bool "Framebuffer Console support"
> >>         depends on FB_CORE && !UML
> >> +       default DRM_FBDEV_EMULATION
> >
> > Sounds good to me, although it looks a bit strange at first sight
> > (FRAMEBUFFER_CONSOLE defaults to n on a system with real fbdev, but
> > y on emulated fbdev?).
>
> And there Maybe default y if (FB || DRM_FBDEV_EMULATION) ?
>
> > So this is the fix for commit a5ae331edb02b ("drm: Drop select
> > FRAMEBUFFER_CONSOLE for DRM_FBDEV_EMULATION").

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds