On Mit, 2010-06-02 at 08:07 +0200, Marius Gröger wrote:
Hello All,
I'm trying the top-of-trunk drm-2.6 trees (both drm-next and drm-radeon-testing) with my Radeon HD 3200 GPU over HDMI. The primary application is mythtv which uses DRM syncing for the frame syncronisation. Now, with the exact same userland software I noticed the introduction of sync gliches in the May-timeframe. The drm-radeon-testing on May 9 was still ok, but both drm-next and drm-radeon-testing at the end of May showed that glitch: every couple of seconds there's a very visual hickup, especially in scroll texts.
Apologies for such an unspecific description, and for what almost seems like a support request for MythTV. I wouldn't post here if I were not 100% sure it must be related with the recent drm changes.
Note that the DRM APIs are intended for use by userspace components of graphics drivers / API libraries, not applications directly. MythTV shouldn't use the DRM directly for synchronization but rather use GLX synchronization APIs.
What I've tried so far:
- I tried bisecting, but I failed to spot the offending commits somehow.
My last hope is this list of experts - for me the git logs look sane, but you guy surely have more insight.
- I tried turning on drm debug=1, but did not see anything suspicious,
especially with relation to the r600 irq handling changes.
- Currently I'm in the process of setting up systemtap to profile the
scheduling, but I'm still on the learning curve :)
I'd be most grateful for any tips and things to try to isolate this issue.
If you have dynamic PM enabled, does disabling that help?