(In reply to comment #13)
> Same problem.
> My graphics cards:
> lspci | grep VGA
> 01:05.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI
> RS880M [Mobility Radeon HD 4225/4250]
> 02:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Park
> [Mobility Radeon HD 5430/5450/5470]
> If radeon.runpm=0 all o.k.
> If manually turning off the dGPU using switcheroo then freeze
>  
> I'm use Ubuntu 14.04 with kernel 3.13.rc1