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From:   Javier Martinez Canillas <javierm@redhat.com>
To:     Arnd Bergmann <arnd@arndb.de>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Arnd Bergmann <arnd@kernel.org>
Cc:     Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Dave Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Helge Deller <deller@gmx.de>,
        Christian =?utf-8?Q?K=C3=B6nig?= <christian.koenig@amd.com>,
        Dave Airlie <airlied@redhat.com>,
        Jim Cromie <jim.cromie@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Arthur Grillo <arthurgrillo@riseup.net>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        linux-fbdev@vger.kernel.org
Subject: Re: [PATCH] drm: fix up fbdev Kconfig defaults
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References: <20230911205338.2385278-1-arnd@kernel.org>
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 <aa935abe-2ccf-4889-a717-4efecc13d48b@app.fastmail.com>
Date:   Tue, 12 Sep 2023 09:55:21 +0200
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"Arnd Bergmann" <arnd@arndb.de> writes:

> On Tue, Sep 12, 2023, at 09:14, Geert Uytterhoeven wrote:
>> On Mon, Sep 11, 2023 at 10:53=E2=80=AFPM Arnd Bergmann <arnd@kernel.org>=
 wrote:

[...]

>
> The only alternative I can think of would be to default-enable
> or force-enable FRAMEBUFFER_CONSOLE for any config that includes
> both VT_CONSOLE and FB_CORE. This would increase defconfig
> builds for systems that currently only want CONFIG_FB for
> either FB_DEVICE or LOGO but don't care about
> FRAMEBUFFER_CONSOLE. I have no idea who uses such a config,
> but I think Javier previously said this was an important
> use case.
>

Yes, IMO that should be a possible combination.

>>> diff --git a/drivers/video/fbdev/core/Kconfig b/drivers/video/fbdev/cor=
e/Kconfig
>>> index 114cb8aa6c8fd..804c2bec9b43c 100644
>>> --- a/drivers/video/fbdev/core/Kconfig
>>> +++ b/drivers/video/fbdev/core/Kconfig
>>> @@ -28,7 +28,7 @@ config FIRMWARE_EDID
>>>  config FB_DEVICE
>>>         bool "Provide legacy /dev/fb* device"
>>>         depends on FB_CORE
>>> -       default y
>>> +       default FB
>>
>> Changing this means possibly causing regressions on systems running
>> an fbdev userspace.
>
> How? FB_DEVICE is a new config that was just split out from
> CONFIG_FB in 6.6-rc1, so nobody should have any defconfig
> that disables CONFIG_FB but relies on the FB_DEVICE default yet.
>

Ah, scratch my previous comment about making this default 'y' then. For
some reasons I thought that FB_DEVICE was added in v6.5 but see now that
commit 701d2054fa31 ("fbdev: Make support for userspace interfaces
configurable") landed in v6.6-rc1:

$ git tag --contains 701d2054fa31 | tail -1
v6.6-rc1

--=20
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat