[NVA8] nouveau screen corruption and X lockup when reclocking

Submitted by Max Sydorenko

Assigned to Nouveau Project

Link to original bug (#89273)

Description

Created attachment 113734
Thinkpad T410, Quadro NVS 3100M (256M GDDR3) vbios dump

Kernel: 3.19.1
Hardware: Thinkpad T410, Quadro NVS 3100M (256M GDDR3) [similar hw but different VRAM compared to bug 88415]
Problem: reclocking between pstates 3 and 7 is flawless, but reclocking to pstate f causes problems.
Possible scenarios:

1. X server is not running, trying to reclock from the fb.
   echo f > pstate
   Image gets corrupted (vertical flickering lines), but there is no lockup and after
   echo 7 > pstate
   everything gets back to normal. After that system works just fine.
   Dmesg attached (with nouveau.debug=debug)
   

2. X server is running.
echo f > pstate
Screen gets corrupted in similar fashion, but system locks up and after few second stops to respond even to SysRq.
I managed to get dmesg for this scenario too.

I also mmiotraced functioning reclocking with the nvidia blob. Trace is quite large (120MB). Should I truncate it somehow to upload, or just provide as is?

**Attachment 113734**, "Thinkpad T410, Quadro NVS 3100M (256M GDDR3) vbios dump":
vbios.dump