X freezes randomly due to radeon

[x_puma_x]

Hi All,

I recently did a fresh install of archlinux with KDE on my notebook and since 
then I get seemingly random freezes (varying lenght) of the X server.
During the freezes everything on the screen stops moving but music keeps 
playing and I am still able to ssh onto the machine.

With the help of some guys over at freenode I think I was able to find out that 
the freezes are caused by the radeon driver.

So when I run htop via ssh during one of the freezes I see that /usr/bin/X has 
the state "D for disk sleep (uninterruptible)".
There is nothing getting logged to either dmesg or /var/log/Xorg.0.log .
But I took a snapshot of /proc/$(pidof X)/stack and attached them.
During normal work it looks like stack_good.txt and during freezes it always 
looks like stack_during_freeze.txt

Any ideas?

uname:
-----
Linux arch 3.9.3-1-ARCH #1 SMP PREEMPT Sun May 19 22:50:29 CEST 2013 x86_64 
GNU/Linux

lspci:
-----
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] 
RV635/M86 [Mobility Radeon HD 3650]

pacman:
-----
Name           : xf86-video-ati
Version        : 1:7.1.0-3
-----
Name           : xorg-server
Version        : 1.14.1-1

--
x_puma_x
-------------- next part --------------
[<ffffffff8119d9c9>] poll_schedule_timeout+0x49/0x70
[<ffffffff8119e30f>] do_select+0x53f/0x670
[<ffffffff8119e64c>] core_sys_select+0x20c/0x310
[<ffffffff8119e7f9>] sys_select+0xa9/0xf0
[<ffffffff814d9e9d>] system_call_fastpath+0x1a/0x1f
[<ffffffffffffffff>] 0xffffffffffffffff
-------------- next part --------------
[<ffffffffa060f864>] radeon_fence_wait_seq+0x1e4/0x590 [radeon]
[<ffffffffa061021b>] radeon_fence_wait+0x2b/0x60 [radeon]
[<ffffffffa06108f1>] radeon_sync_obj_wait+0x11/0x20 [radeon]
[<ffffffffa05a1811>] ttm_bo_wait+0x91/0x190 [ttm]
[<ffffffffa05a4efc>] ttm_bo_move_accel_cleanup+0x9c/0x350 [ttm]
[<ffffffffa0610dd2>] radeon_move_blit.isra.7+0xc2/0x160 [radeon]
[<ffffffffa06116ba>] radeon_bo_move+0xaa/0x1e0 [radeon]
[<ffffffffa05a3065>] ttm_bo_handle_move_mem+0x255/0x5f0 [ttm]
[<ffffffffa05a3592>] ttm_bo_evict+0x192/0x360 [ttm]
[<ffffffffa05a38be>] ttm_mem_evict_first+0x15e/0x200 [ttm]
[<ffffffffa05a3c11>] ttm_bo_mem_space+0x2b1/0x360 [ttm]
[<ffffffffa05a426a>] ttm_bo_move_buffer+0xca/0x150 [ttm]
[<ffffffffa05a438a>] ttm_bo_validate+0x9a/0x110 [ttm]
[<ffffffffa0612be4>] radeon_bo_fault_reserve_notify+0x94/0xc0 [radeon]
[<ffffffffa05a609d>] ttm_bo_vm_fault+0x5d/0x370 [ttm]
[<ffffffffa0610aec>] radeon_ttm_fault+0x4c/0x70 [radeon]
[<ffffffff811480bf>] __do_fault+0x6f/0x580
[<ffffffff8114b743>] handle_pte_fault+0x93/0xaa0
[<ffffffff8114d8cd>] handle_mm_fault+0x2bd/0x650
[<ffffffff814d5cb0>] __do_page_fault+0x1d0/0x5c0
[<ffffffff814d60ae>] do_page_fault+0xe/0x10
[<ffffffff814d2d88>] page_fault+0x28/0x30
[<ffffffffffffffff>] 0xffffffffffffffff