View Full Version : [ubuntu] 12.04 with Sandy Bridge HD3000 doesn't work with my projector :(

June 12th, 2012, 12:08 PM
I have a Core i3 2120 in an Zotac H67ITX-C-E.

Attached to my old Sony 1080i HD TV everything works fine. Ubuntu boots. X.org uses the intel drivers. Even hardware video decoding works perfectly.

Attached to my Optoma 1080p projector things start going horribly wrong. Ubuntu boots, but as soon as the Ubuntu logo comes up the screen goes black and my projector says there's no signal. I can SSH into the system however, and Xorg.0.log seems to think everything is fine, but there's nothing on the screen. I can even unplug it, and plug it into my HDTV again and it will switch modes down to 1080i and give me graphics.

I've tried disabling KMS using nomodset and i915.modeset=0 and even acpi=off as suggested on the Debian Wiki (http://wiki.debian.org/KernelModesetting) but all of these result in a system that won't even boot. I just get a black screen. Not even the no signal warning from my projector. (I'm quite surprised this doesn't trigger a fall back to the VESA X.org driver.)

I've tried xorg-edgers, that doesn't change the behaviour. I've tried the 3.4 kernel from quantal. The only thing that makes any difference is using an old 2.6.32-35 kernel. That results in a system that at least boots, but X.org falls back to the VESA driver so hardware video decoding doesn't work, and I need that for this system to be usable. (If I remove the xserver-xorg-video-intel driver I get no signal on my projector or my HDTV when I switch it over and X seems to have loaded the FBDEV driver instead of the VESA one. This seems a bit weird...)

I've tried using Xrandr to force the mode to 480p. This works fine on the HDTV, but not at all on the projector. Xrandr and the X.org log all show it getting all the right EDID info from my displays too. (Sadly I only have the one full 1080p display, I do have a 1050p monitor I can try it with though...)

And yes, my projector works perfectly fine with various other 1080p inputs :) Until recently I was running 12.04 on an Intel Atom with NVidia ION graphics. This ran perfectly at 1080p on my projector, so this seems to be an interaction between my projector, sandy bridge and the intel x.org drivers.

Any ideas where to go next? I've exhausted my usual bag of tricks :(

June 12th, 2012, 05:28 PM

Using the latest drm-intel kernel from http://cgit.freedesktop.org/~danvet/drm-intel/log/?h=drm-intel-next-queued I've managed to get it working. Sort of. (Thanks to danvet on the Intel graphics IRC.)

If I boot normally, I get a soft lockup error and the boot hangs forever. If I boot into recovery mode, with nomodeset removed from the boot line, and then hit resume, I get the same error. Even trying to just enable networking in recovery causes a soft lockup.

However. If I go into a root console and run mountall --force-fsck (to emulate what the recovery console does) it boots up fine!

I haven't worked out what causes the soft lockup yet, or a sensible way to work around it normally...