Comment 0 for bug 292234

Binary package hint: libgl1-mesa-dri

When I leave my Lenovo X61 Tablet idle for a while in Intrepid it sometimes freezes. All that's left showing is the desktop background, the mouse moves, but nothing can bring it back. When I ssh in Xorg is at 100% cpu. The stack trace looks like this:
#0 0xb7fcc430 in __kernel_vsyscall ()
#1 0xb7c8a1a9 in ioctl () from /lib/tls/i686/cmov/libc.so.6
#2 0xb7f974ab in drmCommandWrite () from /usr/lib/libdrm.so.2
#3 0xa7597cd6 in intelWaitIrq () from /usr/lib/dri/i965_dri.so
#4 0xa7591f74 in ?? () from /usr/lib/dri/i965_dri.so
#5 0xa758b3bc in ?? () from /usr/lib/dri/i965_dri.so
#6 0xa758a712 in dri_fence_wait () from /usr/lib/dri/i965_dri.so
#7 0xa758de0d in intelCopyBuffer () from /usr/lib/dri/i965_dri.so
#8 0xa7590620 in intelSwapBuffers () from /usr/lib/dri/i965_dri.so
#9 0xa75875a7 in ?? () from /usr/lib/dri/i965_dri.so
#10 0xb7aefac4 in ?? () from /usr/lib/xorg/modules/extensions//libglx.so
#11 0xb7ae22ce in ?? () from /usr/lib/xorg/modules/extensions//libglx.so
#12 0xb7ae5c0a in ?? () from /usr/lib/xorg/modules/extensions//libglx.so
#13 0x0808c89f in Dispatch ()
#14 0x08071d1d in main ()

strace of the Xorg process shows the same ioctl over and over again:
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0
ioctl(12, 0x40046445, 0xbfece618) = 0

with an occasional sigalrm:
--- SIGALRM (Alarm clock) @ 0 (0) ---
sigreturn() = ? (mask now [])

I'm running libgl1-mesa-dri 7.2-1ubuntu2.