Bug#783449: linux-image-3.16.0-0.bpo.4-amd64: Xorg fails to start with Radeon HD 7600M on Vostro 3560 after upgrade to 3.16

[Vincas Dargis <vindrg@gmail.com>]

2016-02-22 15:43 GMT+02:00 Andreas Beckmann <anbe@debian.org>:
> Does that conbination even build the kernel module?

Well, actually, I just figured it out that it was not successfully
built. linux-headers-3.16.0-0.bpo.4-amd64 packages was missing.

Now after installing headers and reinstalling fglrx-modules-dkms I
have X working, BUT with strange flickering artifacts when enabling
multiple monitor support on KDE:

https://www.youtube.com/watch?v=uLdLvdl3r0Q

I did aticonfig --initial=dual-head to generate new xorg.conf

Works OK with 3.2 kernel, or with 3.16 but only without external monitor.