Comment 2 for bug 30179

I can confirm this bug. This is a genuine issue in dapper.
Even in my case this happened after I did a suspend to RAM.
The suspend to RAM worked fine and woke up nicely too, but X started locking up after I restarted.
My error log is also identical --
Error in I830WaitLpRing(), now is -46365282, start is -46367283
pgetbl_ctl: 0x2ffe0001 pgetbl_err: 0x0
ipeir: 0 iphdr: 2000001
LP ring tail: 50 head: 0 len: 1f001 start 0
eir: 0 esr: 0 emr: ffff
instdone: efc1 instpm: 12
memmode: 108 instps: 42
hwstam: ffff ier: 2 imr: 9 iir: a0
space: 130984 wanted 131064
(II) I810(0): [drm] removed 1 reserved context for kernel
(II) I810(0): [drm] unmapping 8192 bytes of SAREA 0xefcab000 at 0xb7b17000

Fatal server error:
lockup