My last comment seems to be wrong - the crash just happened with KDE, so no direct connection to running Unity. System worked fine before upgrading to 14.04.
These are the last lines of my dmesg when the screen is freezing and I have to log into the machine to manually shutdown/reboot: [ 6835.834293] nouveau E[ PFIFO][0000:01:00.0] DMA_PUSHER - ch 3 [Xorg[1488]] get 0x00200327a8 put 0x0020032810 ib_get 0x000001ce ib_put 0x00000229 state 0x80000000 (err: INVALID_CMD) push 0x00400040 [ 6898.370384] nouveau E[ DRM] GPU lockup - switching to software fbcon [ 6917.457234] nouveau E[Xorg[1488]] failed to idle channel 0xcccc0000 [Xorg[1488]] [ 6932.456948] nouveau E[Xorg[1488]] failed to idle channel 0xcccc0000 [Xorg[1488]] [ 6932.557581] soffice.bin[4240]: segfault at 8c906a80 ip 00007fbe3af6946d sp 00007fffee43ad00 error 4 in libc-2.19.so[7fbe3af2d000+1bc000] [ 6947.616789] nouveau E[kwin[3648]] failed to idle channel 0xcccc0000 [kwin[3648]] [ 6962.616620] nouveau E[kwin[3648]] failed to idle channel 0xcccc0000 [kwin[3648]] [ 6962.617763] nouveau E[ PFB][0000:01:00.0] trapped read at 0x0020012030 on channel 0x0001f95c [unknown] SEMAPHORE_BG/PFIFO_READ/00 reason: PAGE_NOT_PRESENT [ 6962.617887] nouveau E[ PGRAPH][0000:01:00.0] TRAP_TPDMA_RT - TP 0 - Unknown fault at address 0040310000 [ 6962.617919] nouveau E[ PGRAPH][0000:01:00.0] TRAP_TPDMA_RT - TP 0 - e0c: 00000000, e18: 00000000, e1c: 00000000, e20: 00002a00, e24: 00030000 [ 6962.617960] nouveau E[ PGRAPH][0000:01:00.0] TRAP [ 6962.617980] nouveau E[ PGRAPH][0000:01:00.0] ch 5 [0x001f95c000 kwin[3648]] subc 3 class 0x8597 mthd 0x15e0 data 0x00000000 [ 6962.618023] nouveau E[ PFB][0000:01:00.0] trapped write at 0x0040310000 on channel 0x0001f95c [kwin[3648]] PGRAPH/PROP/RT0 reason: PAGE_NOT_PRESENT [ 6962.657548] nouveau E[ PGRAPH][0000:01:00.0] magic set 0: [ 6962.657573] nouveau E[ PGRAPH][0000:01:00.0] 0x00408604: 0x1c082f03 [ 6962.657595] nouveau E[ PGRAPH][0000:01:00.0] 0x00408608: 0x0040aa0b [ 6962.657617] nouveau E[ PGRAPH][0000:01:00.0] 0x0040860c: 0x80000432 [ 6962.657639] nouveau E[ PGRAPH][0000:01:00.0] 0x00408610: 0x31000000 [ 6962.657660] nouveau E[ PGRAPH][0000:01:00.0] TRAP_TEXTURE - TP0: Unhandled ustatus 0x00000003 [ 6962.657688] nouveau E[ PGRAPH][0000:01:00.0] TRAP [ 6962.657709] nouveau E[ PGRAPH][0000:01:00.0] ch 5 [0x001f95c000 kwin[3648]] subc 4 class 0x502d mthd 0x08dc data 0x0000042c [ 6962.657752] nouveau E[ PFB][0000:01:00.0] trapped write at 0x0040384200 on channel 0x0001f95c [kwin[3648]] PGRAPH/PROP/RT0 reason: PAGE_NOT_PRESENT [ 6962.873930] nouveau E[ PFB][0000:01:00.0] trapped read at 0x0040acc500 on channel 0x0001faa8 [Xorg[20027]] PGRAPH/TEXTURE/00 reason: PAGE_NOT_PRESENT Not sure what else I can provide to give more hints. Is it a hardware problem with the graphics card or a bug in X/noveau? ** Attachment added: "dmesgCrashWithinKDE.txt" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1314405/+attachment/4119079/+files/dmesgCrashWithinKDE.txt -- 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/1314405 Title: Screen freezes due to Xorg crashed SIGABRT and noveau error To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1314405/+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