Created attachment 175791 [details]
picture of trace
Boot regression between 4.1-rc1 and 4.1-rc2
04:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV350 [Radeon 9550/9600/X1050 Series]
Attached picture shows trace.
I guess full bisect is not needed.
ps. https://lkml.org/lkml/2015/5/4/491 looks like it might be related.
Reverting commit 0f55db36d49d45b80eff0c0a2a498766016f458b fixes it for me too.
Created attachment 175801 [details]
This patch should fix it.
Patch fixed it.