Bug#840897: general: framebuffer modules for non-dri graphics cards are not loaded

[Ben Hutchings]

On Sun, 30 Aug 2020 19:08:00 +0200 Michael Biebl <biebl at debian.org> wrote:
> Control: reassign -1 udev
> Control: tags -1 + moreinfo
> 
> Am 30.08.20 um 12:21 schrieb Chris Hofstaedtler:
> > Control: reassign -1 systemd
> > 
> > * Michal Suchanek <hramrach at gmail.com>:
> >> So I would like the fbdev modules removed from whatever blacklist prevents
> >> loading them and have them loaded on systems that don't have dri modules to
> >> handle graphics.
> > 
> > AFAICT systemd ships the fbdev blacklist nowadays, reassigning
> > there.
> 
> The udev package does (but it's src:systemd, so close enough) in
> /lib/modprobe.d/fbdev-blacklist.conf
> 
> I don't know the history behind this file though, it predates the
> udev/systemd merge and a quick search in the old src:udev package did
> not really yield anything useful.
> 
> Hopefully Marco can chime in here and provide some context why it was
> added and if it's still required thoday.

The old-style fbdev drivers generally cannot coexist with user-mode
graphics drivers or DRM drivers for the same devices (but the latter
can coexist with each other).  The fbdev API provides very little
opportunity for X graphics acceleration, so it's generally preferable
to use X with user-mode graphics drivers (or the newer combined DRM/KMS
drivers).  Therefore the fbdev drivers were blocked from auto-loading
by default.

I believe this file used to be a conffile in /etc so that it was
possible to override it in case the user prefers the fbdev driver.

This does not explain why listing atyfb in a modules list does not
work; the "blacklist" directive should not affect that.

Ben.

-- 
Ben Hutchings
The Peter principle: In a hierarchy, every employee tends to rise to
their level of incompetence.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part
URL: <http://alioth-lists.debian.net/pipermail/pkg-systemd-maintainers/attachments/20200901/8960c17c/attachment.sig>