Created attachment 112158 [details]
dmesg log

steps to reproduce:
1. launch anything through discrete videocard e. g. DRI_PRIME=1 glxgears

I expected that program will run through discrete videocard, but after little
time xorg hanged.

Ubuntu 14.10 64-bit, kernel 3.18.1, lastest mesa and drivers from oibaf ppa.

0a:00.0 Display controller: Advanced Micro Devices, Inc. [AMD/ATI] Sun LE
[Radeon HD 8550M / R5 M230] (rev ff)
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated
Graphics Controller (rev 0b)

cat /sys/kernel/debug/vgaswitcheroo/switch 
0:IGD:+:Pwr:0000:00:02.0
1:DIS: :DynOff:0000:0a:00.0