Created attachment 1231321 [details]
dmesg.3.9.5-301.fc19.full trace

Description of problem:

Impossible to boot if 'nomodeset' is not set.  The system hangs during the drm initialisation.
Last kernel version working is 3.9.5-301.fc19.i686.PAE
Tested all versions after 3.9.5-301.fc19 without success.


Version-Release number of selected component (if applicable):
4.8.13-300.fc25.x86_64 

How reproducible:
My system is Laptop hp dv6 with ATI Mobility Radeon HD 5000 Series
If modeset is enabled, when it  reach the drm initialization, it hangs forever.
.

Actual results:


Expected results:


Additional info: In order to narrow the problem I performed the following steps:
   -boot in nomodeset
   -issued command: modprobe radeon modeset=1
   -Now system is completely hung.
   -reboot in nomodeset and get the dmesg trace. See file jctl.fail and fetch pattern '==============' to see what's happens when modeset is enabled by command modprobe.

I made the same test with 3.9.5-301.fc19 on the SAME machine:
   -See file dmesg.3.9.5-301.fc19.full the full dmesg trace.
   -See file dmesg.3.9.5-301.fc19 that contain only the drm traces.