Bug 15164

Summary: PTIMER broken in DRM (regression)
Product: xorg Reporter: Pekka Paalanen <ppaalanen>
Component: Driver/nouveauAssignee: Nouveau Project <nouveau>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:

Description Pekka Paalanen 2008-03-21 15:16:17 UTC 
The commit 1021799b6ca6b195ad2d5f002e45668f69c44651 in DRM, http://gitweb.freedesktop.org/?p=mesa/drm.git;a=commit;h=1021799b6ca6b195ad2d5f002e45668f69c44651 "nouveau: do not set on-board timer's numerator/denominator to bad values" breaks my nv20 (gf3) card.

When starting X, mode is set, I get a screen with colorful garbage on top, black&white noise on the bottom, and black in the middle for couple of seconds during which mouse cursor moves fine. Then I'm back in text console with a kernel gone out to lunch.

There are two problems:
1. the mentioned commit apparently also breaks PTIMER, and
2. nouveau_fifo_free() uses PTIMER for a timeout, which will never happen, hence the kernel becomes a zombie.

While the kernel is a zombie, I can SysRq tErminate, after which I can SysRq show Program counter, which says it is in nouveau_fifo_free. All I can do is SysRq reBoot.

Reverting the mentioned commit fixes the problem 1, and consequently the problem 2. does not trigger.
Comment 1 Stuart Bennett 2008-03-25 11:40:35 UTC 
Reproduced, and hopefully fixed, thanks :)
Comment 2 Pekka Paalanen 2008-03-26 11:55:41 UTC 
Yes, this fixed the issue.

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