Bug#884116: linux-image-4.9.0-4-amd64: screen atrifacts then crash

[Sylvain <beuc@beuc.net>]

Hi,

I also get screen artifacts with the new -4 and -5 kernels:
- display going on/off/on regularly, usually on first key press after
switching between different screens in a multi-display setup
- current window briefly flickering, usually on first key press after
switching between different screens in a multi-display setup
- main display's left origin briefly shifted to the right causing a
"wrapping" effect

I didn't experience a system crash though.

Cheers!
Sylvain