The problem seems to be connected to unity. If I run a KDE session I wasn't able to reproduce the problem, but unity just freezes after running a while without me actively doing anything with the box (audio was running).
<snip> [ 5080.510423] nouveau E[ PGRAPH][0000:01:00.0] PGRAPH TLB flush idle timeout fail [ 5080.511637] nouveau E[ PGRAPH][0000:01:00.0] PGRAPH_STATUS : 0x001e0001 BUSY ENG2D UNK34XX TPRAST TPROP [ 5080.512881] nouveau E[ PGRAPH][0000:01:00.0] PGRAPH_VSTATUS0: 0x00000000 [ 5080.514050] nouveau E[ PGRAPH][0000:01:00.0] PGRAPH_VSTATUS1: 0x0000002d [ 5080.515209] nouveau E[ PGRAPH][0000:01:00.0] PGRAPH_VSTATUS2: 0x00148000 ENG2D </snip> See attached dmesg before a reboot in order to see more details. ** Attachment added: "dmesg saved by ssh after the screen freeze happens" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1314405/+attachment/4107105/+files/dmesg_20140505.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