On Sun, Mar 13, 2011 at 10:08 AM, Anders Eriksson aeriksson@fastmail.fm wrote:
Hi,
I've found what I guess is a radeon (or drm/kms) regression post 2.6.35. I've got my TV conneced to my RS690G over HDMI, and the display has always been jittery after POST and at the GRUB screen. Pre-KMS, the X server (or driver got it sorted), and when KMS started, the display stabilized right after the kernel driver was initiated. However, post 2.6.35, I see the jitter is back.
I've spent the last month trying to bisect it, but pretty much failed. It appears that versions closer to 2.6.38-rcX are more prone to display jitter, while 2.6.36 or so can have many successful runs. It also appears to be related to device power-on order, or so I've come to believe; A stable display can turn jittery, just by power cycling the TV.
I've uploaded a video of a 38-rc8 boot: http://www.easy-share.com/1914220540/2.6.38-rc8_bad_x.mp4
You'll see jitter at the POST screen and GRUB. When KMS kicks in it stabilizes, and when Freevo starts X, it's back to jitter.
Does plain X or gnome/kde jitter too or just freevo?
Alex
The jitter is always of the same kind. It looks like an old tv set which loses sync. The contents on the display is, for a split second, placed at the wrong part of the screen (vertically and to some extent horizontally), and every 5-15 seconds or so, there is a big reset when the TV tries to restart things (I guess). At the resets, thee is a loud 'ping' in the nearby stereo too...
During the bisect (and a t 38-rc8) I've seen this both at the console (post KMS) and in X, so I'm not sure where the error is. I hope some of you can get a better idea of where to hunt for the bug by looking at the video.
-Anders