I go to log in to Ubuntu 13.10. BIOS starts fine, GRUB starts fine, I hit enter on Ubuntu.
Unity-greeter pops up partially (login screen, one or two menu bar items, but no background image and sometimes no password field). If I type something immediately, for the first second or so it will receive the input, but it then locks up and crashes. I can jump into tty1-6 and login fine, switching back often results in a blank screen, sometimes with a blinking cursor. Usually, it either maintains this until freezing me out entirely (that is, the screen simply locks up and does not update when I try to change from a tty to the GUI.
I have discovered a workaround ritual that seems to consistently allow me to log in. If, upon loading the unity-greeter, I manage to type some input to the password field, then switch and log in to a tty after unity-greeter crashes, then perform a command (e.g. ls, or more often dmesg), then when I switch back the greeter will have worked out its problems and be behaving normally.
Upon logging in, the screen goes black and becomes unresponsive for about 30 seconds before finally bringing me to my desktop with unity and compiz and such running properly. Usually an apport crash report pops up soon for both unity-greeter and lightdm.
I don't know what sorts of files will be relevant for people to help me; I'm still a bit of a novice. If more is needed, I'll gladly provide it. For now, here's a few possibly relevant parts of the dmesg output (the whole of which is viewable here:
[ 0.115538] ACPI BIOS Warning (bug): Incorrect checksum in table [TAMG] - 0xD3, should be 0xD2 (20130517/tbprint-204)
No idea what that means.
[ 7.329862] Linux video capture interface: v2.00 [ 7.476618] [drm] Memory usable by graphics device = 2048M [ 7.476624] i915 0000:00:02.0: setting latency timer to 64 [ 7.488871] i915 0000:00:02.0: irq 47 for MSI/MSI-X [ 7.488877] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010). [ 7.488877] [drm] Driver supports precise vblank timestamp query. [ 7.496380] [drm] Wrong MCH_SSKPD value: 0x16040307 [ 7.496382] [drm] This can cause pipe underruns and display issues. [ 7.496383] [drm] Please upgrade your BIOS to fix this. [ 7.496413] [drm] forcing VGA-1 connector OFF
I upgraded my BIOS, never fixed this problem. The VGA-1 connector is off on purpose, though, as per the workaround solution to this problem. Maybe it's there because of that?
[ 34.600943] show_signal_msg: 162 callbacks suppressed [ 34.600947] unity-greeter: segfault at 18 ip 00007f25b678c400 sp 00007fffbdb88f38 error 4 in libgdk-3.so.0.800.6[7f25b6755000+8f000] [ 37.588406] init: lightdm main process (1044) terminated with status 1 [ 42.798914] 6:3:1: cannot get freq at ep 0x82 [ 47.795281] 6:3:1: cannot get freq at ep 0x82
The segfault is specifically occurring in gtk_window_get_type_hint, according to the crash report.
Thanks for reading this far. I depend on this machine for schoolwork and independent coding projects, so having to rely on a lengthy, time-sensitive, superstitious ritual to boot properly makes me very nervous about its continued usability.