Re: X unkillable in R state sometimes on startx , /proc/sysrq-trigger T output attached

[Nix <nix@esperi.org.uk>]

On 26 Oct 2005, Dave Airlie said:
> Your getting an X hang which is usually a DRM/AGP or X configuartion problems..

Indeed. As a random example, when I installed my new Radeon 9250 last
week, I flipped the AGPMode to 8 because the card said it was capable of
that... and X went CPU-mad within seconds of starting 3D rendering.
Looking at the kernel logs made the cause clear:

Oct 25 22:09:08 hades info: kernel: agpgart: Putting AGP V2 device at 0000:00:00.0 into 1x mode

Whether the cause was that X thought it was using 8x and the kernel
thought it was using 1x, I don't know, but changing it to 4 brought
everything into agreement and eliminated the hangs.

(This was with X.org 6.8.99.901.)


So AGP is indeed one of those things which a misconfiguration of can
cause all sorts of lockup-like problems. (Just like misconfiguring any
of the other buses in the system, I suppose.)

-- 
`"Gun-wielding recluse gunned down by local police" isn't the epitaph
 I want. I am hoping for "Witnesses reported the sound up to two hundred
 kilometers away" or "Last body part finally located".' --- James Nicoll