CIK hangs with kernel 3.15, bisected

[Marek Olšák]

Hi Christian,

This commit which first appeared in 3.15-rc1 causes hangs on Bonaire:

commit 6d2f2944e95e504a7d33385eeeb9bb7fcca72592
Author: Christian König <christian.koenig at amd.com>
Date:   Thu Feb 20 13:42:17 2014 +0100

    drm/radeon: use normal BOs for the page tables v4

    No need to make it more complicated than necessary,
    just allocate the page tables as normal BO and
    flush whenever the address change.

    v2: update comments and function name
    v3: squash bug fixes, page directory and tables patch
    v4: rebased on Mareks changes

    Signed-off-by: Christian König <christian.koenig at amd.com>


Reverting the commit gives me a lot of merge conflicts.

The simplest way to reproduce the hangs is to run piglit with these parameters:
-t texelFetch.fs

Some of the tests allocate a lot of MSAA textures and the tests also
run in parallel, which creates a lot of memory pressure and probably
causes buffer evictions.

Any idea what is wrong with it?

Thanks,

Marek