https://bugs.freedesktop.org/show_bug.cgi?id=70687
--- Comment #5 from Teofilis.Martisius@gmail.com --- (In reply to comment #4)
I can confirm that I have a similar issue on 3.12.0. I have Asus K73TA laptop with AMD APU A6-3400M and a discrete card Radeon 6550M.
VGA Switcheroo device was created successfully with 3.11, but disappeared on 3.12.0. Error from dmesg:
...
I think the issue went away in Kernel 3.12.2. Vgaswitcheroo in /sys/kernel/debug does get created successfully and there are no "cut here" error traces in dmesg.
Teo