Messages in this thread | | | Date | Tue, 15 Mar 2011 17:08:25 -0400 | Subject | Re: Radeon jittery post 2.6.35 | From | Jerome Glisse <> |
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On Tue, Mar 15, 2011 at 4:58 PM, Anders Eriksson <aeriksson@fastmail.fm> wrote: > On 03/14/11 23:22, Alex Deucher wrote: >> 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. >> >> > > Some further testing on a clean rc8 suggests that the jitter seen > there can reliably be removed by power cycling the TV while in X, > or starting X with the TV off. > > I'm tempted to think that something makes too much out of bad > info collected from the TV, and falls backs to saner defaults if > the TV has nothing to say. > > I've seen in the logs that the EDID is disliked: > [drm:radeon_dvi_detect] *ERROR* HDMI-A-1: probed a monitor but > no|invalid EDID > Not sure if that is related though (cannot seem to be able to provoke > that error message right now) > > -A
EDID failure could very well explain it, EDID retrieval seems to fails on some GPU under some circonstance (when there is CPU load that interfer with i2c timing i guess). Does the log have the edid failure message when the tv is jittering ? Or is it the otherway around ?
Cheers, Jerome -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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