Triggering ENOMEM from ttm_bo_move_buffer in ttm_bo_validate

[Dr. David Alan Gilbert]

I can reliably trigger a message of the form:
[  443.785343] [drm:radeon_cs_ioctl] *ERROR* Failed to parse relocation -12!

on my HD4350 (Ubuntu Maverick, 64bit).  The setup I can trigger this in
(although I've not tried hard to vary it) is:

    KDE with desktop effects
    viewing Google Maps in Chromium-browser (daily ppa build of the browser)
    zooming in and then zooming back out

-12 is -ENOMEM and I added some debug and have followed it back:
[  443.785331] [drm:ttm_bo_validate] *ERROR* ttm_bo_validate: ttm_bo_move_buffer gave ENOMEM
[  443.785338] [drm:radeon_bo_list_validate] *ERROR* radeon_bo_list_validate: ttm_bo_validate gave NOMEM
[  443.785343] [drm:radeon_cs_ioctl] *ERROR* Failed to parse relocation -12!

i.e. ttm_bo_move_buffer gives ENOMEM in its call from ttm_bo_validate
called from radeon_bo_list_validate called from radeon_cs_ioctl.

At this point I don't really understand the data structures it's
dealing with so I'm a bit lost, but suggestions for where to add
more debug would be appreciated.

Ubuntu bug 
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/583891
has various people managing to trigger this in different ways.

Dave
-- 
 -----Open up your eyes, open up your mind, open up your code -------   
/ Dr. David Alan Gilbert    |       Running GNU/Linux       | Happy  \ 
\ gro.gilbert @ treblig.org |                               | In Hex /
 \ _________________________|_____ http://www.treblig.org   |_______/