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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 28 Jul 2022 17:16:32 +0200
Message-ID: <CAK8P3a2vJFCJmeMj-vuasUhwa2=2P+hAr=ScGhT21TcjQ1Z8Aw@mail.gmail.com>
Subject: Re: [PATCH 2/2] efi: earlycon: Add support for generic framebuffers
 and move to fbdev subsystem
To:     Markuss Broks <markuss.broks@gmail.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
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        "Paul E. McKenney" <paulmck@kernel.org>,
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        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
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On Thu, Jul 28, 2022 at 4:57 PM Markuss Broks <markuss.broks@gmail.com> wrote:
> On 7/28/22 17:48, Arnd Bergmann wrote:
> > On Thu, Jul 28, 2022 at 4:28 PM Markuss Broks <markuss.broks@gmail.com> wrote:
> >>
> >> Add early console support for generic linear framebuffer devices.
> >> This driver supports probing from cmdline early parameters
> >> or from the device-tree using information in simple-framebuffer node.
> >> The EFI functionality should be retained in whole.
> >> The driver was disabled on ARM because of a bug in early_ioremap
> >> implementation on ARM.
> >>
> >> Signed-off-by: Markuss Broks <markuss.broks@gmail.com>
> >> ---
> >>   .../admin-guide/kernel-parameters.txt         |  12 +-
> >>   MAINTAINERS                                   |   5 +
> >>   drivers/firmware/efi/Kconfig                  |   6 +-
> >>   drivers/firmware/efi/Makefile                 |   1 -
> >>   drivers/firmware/efi/earlycon.c               | 246 --------------
> >>   drivers/video/fbdev/Kconfig                   |  11 +
> >>   drivers/video/fbdev/Makefile                  |   1 +
> >>   drivers/video/fbdev/earlycon.c                | 301 ++++++++++++++++++
> >
> > It looks like this is not actually related to fbdev, and since drivers are
> > moving from fbdev/simplefb towards drm/simpledrm, maybe it would be
> > better to put this into either drivers/gpu/drm/tiny/ or possibly
> > drivers/video/console to let this be used without enabling fbdev?
>
> Ideally this shouldn't depend on anything, because it isn't utilizing
> any of fbdev code and won't be utilizing any of drm/console code. I
> agree that either of those would be a better place for it, but which one
> do you think would suit more for this driver?

I think ideally this would be integrated with simpledrm in the long run,
but I have no idea what that means in terms of future code changes.

Maybe Thomas Zimmermann has an idea here.

        Arnd