Comment 129 for bug 755841

(In reply to comment #72)
> Just as an update from the past post.

Thanks for the update!

> Unfortunately, all my attempts for fixing this properly have failed so far, the
> hardware does not wants to collaborate with the software for inter-ring
> synchronization.

I have a couple questions if you don't mind. In a previous comment, you mentioned that a fix would require work in the kernel, in libdrm and in the X driver. So is a fix really viable within the SNB product cycle? Does it affect Ivy Bridge as well? I ask because I may consider upgrading early to Ivy Bridge if this is no longer a issue.

> So the workaround I used previously still applies - I need to disable
> compositing and use either vaapi or gl rendering, which perform vsync'ed screen
> updates. This way, I see no tearing.

I can still see tearing with GL rendering. It's much less noticeable, but it's there. I can see it clearly when I'm watching basketball games in a 1080p TV (using HDMI), specially during the fastbreak, when the camera pans quickly. But yea, it's much better than X11, Xv or anything like that. Is this expected? I tested both with mplayer and VLC (glx output).

I can't even test VAAPI. VLC supports it, but when I enable it, I get 100% CPU usage and less than 1 FPS for some reason. There's the mplayer patches for VAAPI support, but it seems in very bad shape. Is there a test program for VAAPI?

For the record, I'm not running a composite manager.

Thanks for looking into this Eugeni.