WoW has started crashing with my Hd6450. A "git bisect" pinpoints this commit:

862f69fbe1e54e0e9a3c439450a14f0319648b60 is the first bad commit
commit 862f69fbe1e54e0e9a3c439450a14f0319648b60
Author: Marek Olšák <maraeo@gmail.com>
Date:   Sun Jun 30 14:57:17 2013 +0200

    r600g: don't call buffer_wait in buffer_mmap_sync_with_rings

    The winsys should do this, because it measures how much time we spend
    in buffer_map doing synchronization, which can be viewed with the gallium
    HUD.

    Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

:040000 040000 7443defc91af969379873fc85698e78cc0731b12
9a18818193c561b6aff233efc290f7655924cbd1 M    src

WoW's own crash dump analysis is attached, but the relevant part appears to be:

--- Thread ID: 74 [Current Thread] ---
00007FEEB939E2AD              radeon_get_reloc+45
(0000000000000000,0000000000000000,0000000000000000,0000000000000000)
00007FEEB939D6C7              radeon_bo_map+551
(0000000000000000,0000000000000000,0000000000000000,0000000000000000)
00007FEEB933C89B              r600_buffer_transfer_map+107
(0000000000000000,0000000000000000,0000000000000000,0000000000000000)
00007FEEB917A0D7              st_bufferobj_get_subdata+119
(0000000000000000,000

(It turns out that I was running WoW in DXD9 mode rather than OpenGL mode, but
it still shouldn't have crashed.)