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