| From | Geert Uytterhoeven <> | Date | Thu, 7 Jan 2021 09:13:10 +0100 | Subject | Re: [PATCH 5.10 28/63] fbcon: Disable accelerated scrolling |
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On Mon, Jan 4, 2021 at 5:58 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > From: Daniel Vetter <daniel.vetter@ffwll.ch> > > commit 39aead8373b3c20bb5965c024dfb51a94e526151 upstream. > > So ever since syzbot discovered fbcon, we have solid proof that it's > full of bugs. And often the solution is to just delete code and remove > features, e.g. 50145474f6ef ("fbcon: remove soft scrollback code"). > > Now the problem is that most modern-ish drivers really only treat > fbcon as an dumb kernel console until userspace takes over, and Oops > printer for some emergencies. Looking at drm drivers and the basic > vesa/efi fbdev drivers shows that only 3 drivers support any kind of > acceleration: > > - nouveau, seems to be enabled by default > - omapdrm, when a DMM remapper exists using remapper rewriting for > y/xpanning > - gma500, but that is getting deleted now for the GTT remapper trick, > and the accelerated copyarea never set the FBINFO_HWACCEL_COPYAREA > flag, so unused (and could be deleted already I think). > > No other driver supportes accelerated fbcon. And fbcon is the only
Note that there are 32 more drivers using acceleration under drivers/video/fbdev/.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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