Re: [PATCH 0/2] Allow disabling all native fbdev drivers and only keeping DRM emulation

From: Javier Martinez Canillas
Date: Mon Jul 03 2023 - 04:44:45 EST


Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> writes:

> On Fri, Jun 30, 2023 at 10:29:20PM +0200, Javier Martinez Canillas wrote:
>> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> writes:
>> > On Fri, Jun 30, 2023 at 07:38:01PM +0200, Javier Martinez Canillas wrote:
>> >> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> writes:
>> >> > On Fri, Jun 30, 2023 at 12:51:02AM +0200, Javier Martinez Canillas wrote:
>> >> >> This patch series splits the fbdev core support in two different Kconfig
>> >> >> symbols: FB and FB_CORE. The motivation for this is to allow CONFIG_FB to
>> >> >> be disabled, while still having the the core fbdev support needed for the
>> >> >> CONFIG_DRM_FBDEV_EMULATION to be enabled. The motivation is automatically
>> >> >> disabling all fbdev drivers instead of having to be disabled individually.
>> >> >>
>> >> >> The reason for doing this is that now with simpledrm, there's no need for
>> >> >> the legacy fbdev (e.g: efifb or vesafb) drivers anymore and many distros
>> >> >
>> >> > How does simpledrm works with earlycon=efi?
>> >> >
>> >>
>> >> simpledrm isn't for earlycon. For that you use a different driver (i.e:
>> >> drivers/firmware/efi/earlycon.c). I'm just talking about fbdev drivers
>> >> here that could be replaced by simpledrm.
>> >
>> > So, efifb can't be replaced. Please, fix your cover letter to reduce false
>> > impression of the scope of usage of the simpledrm.
>> >
>>
>> Nothing to fixup.
>>
>> You are conflating the efifb fbdev driver (drivers/video/fbdev/efifb.c)
>> with the efifb earlycon driver (drivers/firmware/efi/earlycon.c). I'm
>> talking about the former (which can be replaced by simpledrm) while you
>> are talking about the latter.
>
> Ah, this makes sense!
>
> I remember now that it was (still is?) an attempt to move from efifb to
> simpledrm, but have no idea what the status of that series is.
>

Indeed. And there was were also some patches IIRC to attempt porting the
earlycon efifb to a fbdev or DRM driver, can't remember now.

> --
> With Best Regards,
> Andy Shevchenko
>
>

--
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat