Debugging drm modesetting issues

[David Rees]

I've run Fedora for a long time.  I stuck with Fedora 14 for a long
time as I much preferred Gnome 2 over Gnome 3 and everything just
worked.  Rock solid.

Since F14 went EOL, I've recently upgraded to F16, but I've been
dogged by a couple of stability issues.  The rest I've figured out.

Main one is that the system won't always boot.  Boot process will
continue until it's time for drm/modesetting to take place at which
point instead of getting the resized text, I get a blank screen.
Adding radeon.agpmode=-1 seems to make this more reliable, but still
occasionally hangs.

The system is still responsive - a Ctrl-Alt-Del will reboot the system.

Looking at the logs after the reboot shows nothing - so it's obviously
gotten stuck pretty early in the boot process.

How can I debug this issue so that I might gather information to file
a bug report?

Second issue is that the system is now completely unstable with AMD
Cool'n'Quiet enabled.  Already filed a bug for that one.
https://bugzilla.redhat.com/show_bug.cgi?id=795334  Sucks to waste
electricity when not needed!

-Dave