Further to my comment #7 above, I noticed an xorg-core update today so I tried Unity for a while but it locked up within 30 mins. System died over about 20 secs, i.e. my mouse became sluggish then after about 10 secs it stopped moving completely. Music player stopped a few secs after that and all UI was frozen. I found I could log in remotely via ssh from my laptop and found skype (v4) at the top of the run queue. Killed it (using default kill TERM) but system remained frozen. Found a heap of the following messages in dmesg/kern.log: [ 1413.350588] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08d0 Data 0x00000000 [ 1413.350606] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08d4 Data 0x0000029f [ 1413.350624] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08d8 Data 0x00000000 [ 1413.350641] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08dc Data 0x0000042e [ 1413.350660] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x0110 Data 0x00000000 [ 1413.350679] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x088c Data 0x00000000 [ 1413.350697] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08b0 Data 0x000002a0 [ 1413.350715] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08b4 Data 0x00000487 [ 1413.350733] [drm] nouveau 0000:01:00.0: PFIFO_CACHE_ERROR - Ch 4/2 Mthd 0x08b8 Data 0x00000001
and then [ 2638.295874] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2638.513969] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2638.731928] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2638.950519] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2639.168399] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2639.386458] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2639.604410] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2639.822783] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2640.047224] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2640.265387] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2640.483451] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 [ 2640.701437] [drm] nouveau 0000:01:00.0: nv50cal_space: -16 Another odd thing which I also noticed the previous time this happened - I planned to grab the Xorg.0.log.old file after I rebooted but found that the nouveau driver seems to die (or get killed) and then restarted during my system startup, i.e. Xorg.0.log.old contains: [ 32.513] (II) NOUVEAU(0): NVLeaveVT is called. [ 32.520] (II) NOUVEAU(0): Closed GPU channel 2 [ 32.540] ddxSigGiveUp: Closing log [ 32.540] Server terminated successfully (0). Closing log file. and then the system comes up ok logging in Xorg.0.log. So I lose the real "previous" log file. Even though this happens, there is no abnormal screen "glitch" noticeable to me as the system comes up. Hope all this makes sense and I hope posting this here is appropriate even though I am using xorg-edgers ppa? Looks like an xorg/nouveau bug - but may be something brought on by skype 4? I should add that, like the OP, I am using dual monitors: 2 by 1900x1200. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1012916 Title: [nouveau] 12.04 Unity 3d hard freezes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1012916/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp