[PATCH 1/4] drm/radeon: move ring syncing after bo validation

[Mathias Fröhlich]

Christian,

On Thursday, February 23, 2012 15:18:42 Christian König wrote:
> The function radeon_bo_list_validate can cause a
> bo to move, resulting in a different sync_obj
> and a dependency to wait for this move to finish.
> 
> Signed-off-by: Christian König <deathsimple at vodafone.de>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

I am not sure, but to me this looks like this could fix these kind of gpu 
lockups that I experience since some time every now and then.
The usual symptom is that I get the 

radeon 0000:01:00.0: GPU lockup CP stall for more than 10000msec
GPU lockup (waiting for 0x00682AC3 last fence id 0x00682AC2)
[...]

kernel message. Each time with the fence being off by one like in the example 
above.

If this change has the potential to fix this issue I think this particular 
patch should be considered for the current upstream kernel release.

Mathias