I've hit a new BUG using the same trigger (huge png image in firefox, zoom in and zoom out while the picture is loading):
Nov 27 09:56:14 [kernel] kernel BUG at drivers/gpu/drm/ttm/ttm_bo.c:1134! Nov 27 09:56:14 [kernel] CPU 3 Nov 27 09:56:14 [kernel] Pid: 1867, comm: X Not tainted 2.6.37-rc3-00215-g94ece42-dirty #8 M4A78T-E/System Product Name Nov 27 09:56:14 [kernel] RIP: 0010:[<ffffffff8128b181>] [<ffffffff8128b181>] ttm_bo_check_placement+0x21/0x30 Nov 27 09:56:14 [kernel] RSP: 0018:ffff880118f99b98 EFLAGS: 00010206 Nov 27 09:56:14 [kernel] RAX: 0000000000008000 RBX: ffff88011c610020 RCX: ffffffff812c2d80 Nov 27 09:56:14 [kernel] RDX: 0000000008688000 RSI: ffff88011c610020 RDI: ffff88011c610048 Nov 27 09:56:14 [kernel] RBP: ffff880118f99b98 R08: ffff88011c610020 R09: 0000000000000001 Nov 27 09:56:14 [kernel] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88011ef30508 Nov 27 09:56:14 [kernel] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000008688 Nov 27 09:56:14 [kernel] FS: 00007ff13cc3e700(0000) GS:ffff8800dfd80000(0000) knlGS:0000000000000000 Nov 27 09:56:14 [kernel] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Nov 27 09:56:14 [kernel] CR2: 00007ff13ca7b000 CR3: 000000011c455000 CR4: 00000000000006e0 Nov 27 09:56:14 [kernel] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Nov 27 09:56:14 [kernel] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Nov 27 09:56:14 [kernel] Process X (pid: 1867, threadinfo ffff880118f98000, task ffff88011fe24e00) Nov 27 09:56:14 [kernel] ffff880118f99be8 ffffffff8128d22d ffff880100000001 ffff88011c610048 Nov 27 09:56:14 [kernel] 0000000008688000 ffff88011c610000 ffff88011ef30000 ffff88011c610000 Nov 27 09:56:14 [kernel] 0000000000000000 0000000000000001 ffff880118f99cb8 ffffffff812c3041 Nov 27 09:56:14 [kernel] [<ffffffff8128d22d>] ttm_bo_init+0x17d/0x360 Nov 27 09:56:14 [kernel] [<ffffffff812c3041>] radeon_bo_create+0x151/0x2c0 Nov 27 09:56:14 [kernel] [<ffffffff812c2d80>] ? radeon_ttm_bo_destroy+0x0/0xc0 Nov 27 09:56:14 [kernel] [<ffffffff81120c80>] ? pollwake+0x0/0x60 Nov 27 09:56:14 [kernel] [<ffffffff812d8f1b>] radeon_gem_object_create+0x8b/0x110 Nov 27 09:56:14 [kernel] [<ffffffff8106b5db>] ? __wake_up+0x4b/0x60 Nov 27 09:56:14 [kernel] [<ffffffff812d9358>] radeon_gem_create_ioctl+0x58/0xd0 Nov 27 09:56:14 [kernel] [<ffffffff812d96ed>] ? radeon_gem_wait_idle_ioctl+0xed/0x110 Nov 27 09:56:14 [kernel] [<ffffffff81274efc>] drm_ioctl+0x3bc/0x490 Nov 27 09:56:14 [kernel] [<ffffffff812d9300>] ? radeon_gem_create_ioctl+0x0/0xd0 Nov 27 09:56:14 [kernel] [<ffffffff8111ffaa>] do_vfs_ioctl+0x9a/0x540 Nov 27 09:56:14 [kernel] [<ffffffff81039e9b>] system_call_fastpath+0x16/0x1b Nov 27 09:56:14 [kernel] RIP [<ffffffff8128b181>] ttm_bo_check_placement+0x21/0x30 Nov 27 09:56:14 [kernel] RSP <ffff880118f99b98> Nov 27 09:56:14 [kernel] ---[ end trace d14c91f5f64be308 ]--- Nov 27 09:57:40 [kernel] Emergency Sync complete