System hang when switching configurations

[Tessa Lau]

I use disper to toggle between a 2-head setup (docked laptop + external monitor) and a laptop-only setup (undocked). I created a script that I can call just prior to undocking, which invokes disper with the laptop-only configuration. Sometimes when I run this script, the system hangs with a black screen. The external monitor turns off, but the laptop display goes black with the backlight still on. I don't see a mouse cursor, and no keypresses have any effect. I can't press Ctrl-Alt-Fn to get to a terminal. At this point my only option is to power-cycle the machine.

What can I do to help debug this problem?

Here is my disper.conf, which I invoke with "disper -i < ~tlau/dock/disper-undocked.conf":
backend: nvidia
associated displays: DFP-0
metamode: DFP-0: nvidia-auto-select @1440x900 +0+0
scaling: stretched
xinerama info order: DFP-0

Here are the log messages from the Xorg.0.log around the time of the crash:
[ 39066.373] (II) NVIDIA(0): Setting mode "DFP-0:nvidia-auto-select@1440x900+0+0"
[ 39084.071] (WW) NVIDIA(0): WAIT (2, 6, 0x8000, 0x00007ba8, 0x00007bb8)
[ 39091.071] (WW) NVIDIA(0): WAIT (1, 6, 0x8000, 0x00007ba8, 0x00007bb8)
[ 39094.072] (WW) NVIDIA(0): WAIT (2, 6, 0x8000, 0x00007ba8, 0x00007bc8)
[ 39101.072] (WW) NVIDIA(0): WAIT (1, 6, 0x8000, 0x00007ba8, 0x00007bc8)
(and more of the same)

I have disper version 0.3.0. I'll attach the nvidia-bug-report output below. Is there any other information I can provide to help identify this bug? It's very annoying that undocking my laptop and switching display configurations carries the risk of losing all my work.

Thanks!

[bpedman (bpedman)]

I am having the same problem. I am using the nvidia drivers from the nvidia site directly (rather than the packaged drivers) and have a nvs 4200m...wish I had more helpful information