Hi,

A friend of my has the same problem. He is using:
Linux smi01 2.6.31-20-generic #58-Ubuntu SMP Fri Mar 12 05:23:09 UTC 2010 i686 GNU/Linux (Release 9.10)

Unfortunately the system freezes frequently. Looking into his dmesg learns me that we are facing the same issue as described above. A small tail from dmesg:
[13920.408039] Call Trace:
[13920.408044]  [<c0572b76>] __mutex_lock_slowpath+0xc6/0x130
[13920.408047]  [<c0572a90>] mutex_lock+0x20/0x40
[13920.408068]  [<f84af8fa>] i915_gem_retire_work_handler+0x2a/0x70 [i915]
[13920.408071]  [<c01579de>] run_workqueue+0x6e/0x140
[13920.408083]  [<f84af8d0>] ? i915_gem_retire_work_handler+0x0/0x70 [i915]
[13920.408086]  [<c0157b38>] worker_thread+0x88/0xe0
[13920.408089]  [<c015c180>] ? autoremove_wake_function+0x0/0x40
[13920.408091]  [<c0157ab0>] ? worker_thread+0x0/0xe0
[13920.408093]  [<c015be8c>] kthread+0x7c/0x90
[13920.408095]  [<c015be10>] ? kthread+0x0/0x90
[13920.408097]  [<c0104047>] kernel_thread_helper+0x7/0x10
[14040.408013] INFO: task i915/0:329 blocked for more than 120 seconds.
[14040.408016] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[14040.408019] i915/0        D c08185c0     0   329      2 0x00000000
[14040.408024]  f646df04 00000046 00000001 c08185c0 f6450f28 c08185c0 e7a7e7b7 00000c02
[14040.408030]  c08185c0 c08185c0 f6450f28 c08185c0 e7a7e34d 00000c02 c08185c0 f6445340
[14040.408037]  f6450c90 f6931814 f6931818 ffffffff f646df30 c0572b76 c074ce80 f693181c
[14040.408043] Call Trace:
[14040.408050]  [<c0572b76>] __mutex_lock_slowpath+0xc6/0x130
[14040.408053]  [<c0572a90>] mutex_lock+0x20/0x40
[14040.408075]  [<f84af8fa>] i915_gem_retire_work_handler+0x2a/0x70 [i915]
[14040.408079]  [<c01579de>] run_workqueue+0x6e/0x140
[14040.408091]  [<f84af8d0>] ? i915_gem_retire_work_handler+0x0/0x70 [i915]
[14040.408093]  [<c0157b38>] worker_thread+0x88/0xe0
[14040.408096]  [<c015c180>] ? autoremove_wake_function+0x0/0x40
[14040.408099]  [<c0157ab0>] ? worker_thread+0x0/0xe0
[14040.408101]  [<c015be8c>] kthread+0x7c/0x90
[14040.408103]  [<c015be10>] ? kthread+0x0/0x90
[14040.408105]  [<c0104047>] kernel_thread_helper+0x7/0x10

There is one thing I've observed. With the top command I saw that just one process was continuously running (Normally you will see a few processes). The process was "ica" (iTALC master application)

Tail from kern.log:
Mar 26 20:57:30 smi01 kernel: [14040.408053]  [<c0572a90>] mutex_lock+0x20/0x40
Mar 26 20:57:30 smi01 kernel: [14040.408075]  [<f84af8fa>] i915_gem_retire_work_handler+0x2a/0x70 [i915]
Mar 26 20:57:30 smi01 kernel: [14040.408079]  [<c01579de>] run_workqueue+0x6e/0x140
Mar 26 20:57:30 smi01 kernel: [14040.408091]  [<f84af8d0>] ? i915_gem_retire_work_handler+0x0/0x70 [i915]
Mar 26 20:57:30 smi01 kernel: [14040.408093]  [<c0157b38>] worker_thread+0x88/0xe0
Mar 26 20:57:30 smi01 kernel: [14040.408096]  [<c015c180>] ? autoremove_wake_function+0x0/0x40
Mar 26 20:57:30 smi01 kernel: [14040.408099]  [<c0157ab0>] ? worker_thread+0x0/0xe0
Mar 26 20:57:30 smi01 kernel: [14040.408101]  [<c015be8c>] kthread+0x7c/0x90
Mar 26 20:57:30 smi01 kernel: [14040.408103]  [<c015be10>] ? kthread+0x0/0x90
Mar 26 20:57:30 smi01 kernel: [14040.408105]  [<c0104047>] kernel_thread_helper+0x7/0x10