(In reply to comment #31)
> (In reply to comment #30)
> > 
> >   I've set each register values from fglrx-console.data and call xinit.
> > Lockup again, nothing changes.
> 
> Does the patch in comment 29 fix the issue for you?  That patch is upstream
> now and should be in most stable kernels as well.

  To the pity, no. I've tested Linux 3.12 with the patch already applied and it
changes nothing. My chip is:

$ lspci | grep 'VGA'
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Sumo
[Radeon HD 6480G]

  Is it really a SUMO2 chip or I should open a new bug?