I can trigger the bug with docky anytime I want. Just move quickly through Docky icons with the mouse cursor (https://bugs.launchpad.net/ubuntu/+source/docky/+bug/1451379). I a few seconds the screen will freeze. Most of the times I have to wait for about 30 seconds. I can switch to text (Alt + Ctrl + F1) in the meantime and see that gnome-shell occupies the computer 100%. Nouveau driver writes lots of lines into syslog at the same time. But sometimes everything freezes and only hard reset helps.
It starts like that: May 21 08:35:37 computer gnome-session[8979]: nouveau: kernel rejected pushbuf: Invalid argument May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: krec 0 pushes 1 bufs 19 relocs 0 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000000 00000005 00000004 00000004 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000001 000001b9 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000002 00000007 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000003 0000000a 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000004 0000000b 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000005 00000008 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000006 00000006 00000004 00000000 00000004 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000007 0000019e 00000002 00000000 00000002 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000008 00000013 00000002 00000000 00000002 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000009 0000000d 00000004 00000004 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000a 00000104 00000004 00000004 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000b 00000124 00000002 00000002 00000002 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000c 00000026 00000004 00000004 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000d 00000090 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000e 000001b1 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 0000000f 000001ac 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000010 000001ad 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000011 00000030 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: buf 00000012 000001ba 00000002 00000002 00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: ch0: psh 00000000 000005e7d4 000006045c May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x0004721c May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x0fac6881 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00086ff4 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x12c00000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x04b00000 May 21 08:35:37 computer kernel: [263094.549645] nouveau E[gnome-shell[9087]] multiple instances of buffer 442 on validation list May 21 08:35:37 computer kernel: [263094.549650] nouveau E[gnome-shell[9087]] validate_init May 21 08:35:37 computer kernel: [263094.549652] nouveau E[gnome-shell[9087]] validate: -22 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00146200 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x511f0000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x000000e6 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000040 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00087240 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x000012c0 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x000004b0 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00047224 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000001 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00146fe0 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x42dd0000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000016 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000040 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000000 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00047538 May 21 08:35:37 computer gnome-session[8979]: nouveau: #0110x00000001 And then hundreds of these lines with "nouveau: #..." -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1291574 Title: nouveau DRM GPU lockup, PFIFO unhandled status 0x00800000 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1291574/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
