Error in I830WaitLpRing()

[Phil Roan <proan@earthlink.net>]

I've been getting this error infrequently for some time now.
Rebooting seems to "fix" it, but I wondered if it was a known issue
that had a real solution.

My system is an Intel 845 GVSR motherboard, with up to date Debian
Lenny.  The error causes Xorg to fail.  The relevant part of
/var/log/Xorg.0.log is below:

Error in I830WaitLpRing(), timeout for 2 seconds
pgetbl_ctl: 0x4ffe0001 getbl_err: 0x00000000
ipeir: 0x00000000 iphdr: 0x00000000
LP ring tail: 0x000002a8 head: 0x00000490 len: 0x0001f001 start
0x00000000
eir: 0x0000 esr: 0x0000 emr: 0xff7b
instdone: 0xffc1 instpm: 0x0000
memmode: 0x00000000 instps: 0x00000020
hwstam: 0xfffe ier: 0x0002 imr: 0x053c iir: 0x0080
Ring at virtual 0xaf9fa000 head 0x490 tail 0x2a8 count 32646
        00000410: 000e0000
        00000414: 00000000
        00000418: 00000010
        0000041c: 00aa4000
        00000420: 54f00006
        00000424: 03cc1900
        00000428: 03cc0148
        0000042c: 03d0014c
        00000430: 000e0000
        00000434: 00000000
        00000438: 00000010
        0000043c: 00aa4000
        00000440: 54f00006
        00000444: 03cc1900
        00000448: 03cc014c
        0000044c: 03d00150
        00000450: 000e0000
        00000454: 00000000
        00000458: 00000010
        0000045c: 00aa4000
        00000460: 54f00006
        00000464: 03cc1900
        00000468: 03cc0150
        0000046c: 03d00154
        00000470: 000e0000
        00000474: 00000000
        00000478: 00000010
        0000047c: 00aa4000
        00000480: 54f00006
        00000484: 03cc1900
        00000488: 03cc0154
        0000048c: 03d00158
        00000490: 000e0000
Ring end
space: 480 wanted 131064
(II) intel(0): [drm] removed 1 reserved context for kernel
(II) intel(0): [drm] unmapping 8192 bytes of SAREA 0xf8bc8000 at
0xb7b35000
(II) intel(0): [drm] Closed DRM master.

Fatal server error:
lockup

-- 
Phil Roan
proan@earthlink.net