Graphical artifacts during GDM login

[Michael Schwendt]

On Thu, 30 Apr 2015 19:21:50 +0200, Sébastien Wilmet wrote:

> On Thu, Apr 30, 2015 at 10:59:17AM +0200, Michael Schwendt wrote:
> > This is still an issue with F22, and I'd like a hint on where to report
> > it. Which component? Different video adapters are affected. For me it's
> > ATI Radeon.
> > 
> > After logging in via GDM, lots of small rectangular areas appear at
> > the bottom of the screen until GNOME Shell apears. They are filled
> > with what seems to be old contents from the video memory. It doesn't
> > look pretty, because it looks like corruption.
> 
> I think, but I may be wrong, that atomic mode setting will fix the
> problem:
> https://en.wikipedia.org/wiki/Mode_setting
> 
> Right?

After entering the credentials, there is a small delay, a blank black
screen, video mode is switched, a gray empty screen is displayed, then
colourful artifacts appear at the bottom before GNOME Shell background
zooms in.