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

From: Javier Martinez Canillas
Date: Tue Jul 27 2021 - 07:32:39 EST


On 7/27/21 1:17 PM, Geert Uytterhoeven wrote:

[snip]

>> 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?
>

That's a good question. I don't know if all EFI firmwares are expected
to provide a GOP or not. But even the u-boot EFI stub provides one, if
video output is supported by u-boot on that system.

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

It's another option, yes. I just thought that the use of select was not
encouraged and using depends was less fragile / error prone.

>> 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 ;-)
>

Ok :)

Best regards,
--
Javier Martinez Canillas
Linux Engineering
Red Hat