[PATCH v2] drivers/firmware: fix SYSFB depends to prevent build failures

[Geert Uytterhoeven]

Hi Javier,

On Tue, Jul 27, 2021 at 12:22 PM Javier Martinez Canillas
<javierm at redhat.com> wrote:
> On 7/27/21 12:03 PM, Geert Uytterhoeven wrote:
> >> --- a/drivers/firmware/Kconfig
> >> +++ b/drivers/firmware/Kconfig
> >> @@ -254,7 +254,7 @@ config QCOM_SCM_DOWNLOAD_MODE_DEFAULT
> >>  config SYSFB
> >>         bool
> >>         default y
> >> -       depends on X86 || ARM || ARM64 || RISCV || COMPILE_TEST
> >> +       depends on X86 || EFI
> >
> > Thanks, much better.
> > Still, now this worm is crawling out of the X86 can, I'm wondering
> > why this option is so important that it has to default to y?
> > It is not just a dependency for SYSFB_SIMPLEFB, but also causes the
> > inclusion of drivers/firmware/sysfb.c.
> >
>
> It defaults to yes because drivers/firmware/sysfb.c contains the logic
> to register a "simple-framebuffer" device (or "efi-framebuffer" if the
> CONFIG_SYSFB_SIMPLEFB Kconfig symbol is not enabled).
>
> Not enabling this, would mean that a platform device to match a driver
> supporting the EFI GOP framebuffer (e.g: simple{drm,fb} or efifb) will
> not be registered. Which will lead to not having an early framebuffer.

Do all (embedded) EFI systems have a frame buffer?

Perhaps SYSFB should be selected by SYSFB_SIMPLEFB, FB_VESA,
and FB_EFI?

> The logic used to be in drivers/firmware/efi/efi-init.c, that's built
> in if CONFIG_EFI is enabled. We just consolidated both X86 and EFI:
>
> https://cgit.freedesktop.org/drm/drm-misc/commit/?id=8633ef82f101

Thanks, I'm aware of that commit, as I was just about to reply to it,
when I saw the patch is this thread ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

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