On Mon, Mar 14, 2011 at 6:20 PM, Alex Deucher alexdeucher@gmail.com wrote:
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?
Does this patch help?
diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c index 1d89259..a2bd944 100644 --- a/drivers/gpu/drm/radeon/atombios_crtc.c +++ b/drivers/gpu/drm/radeon/atombios_crtc.c @@ -524,7 +524,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc, if ((rdev->family == CHIP_RS600) || (rdev->family == CHIP_RS690) || (rdev->family == CHIP_RS740)) - pll->flags |= (/*RADEON_PLL_USE_FRAC_FB_DIV |*/ + pll->flags |= (RADEON_PLL_USE_FRAC_FB_DIV | RADEON_PLL_PREFER_CLOSEST_LOWER);
if (ASIC_IS_DCE32(rdev) && mode->clock > 200000) /* range limits??? */
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