[PATCH] drm/radeon: fence virtual address and free it once idle [3.5] v2

[Greg KH]

On Fri, Aug 03, 2012 at 03:57:19PM -0400, j.glisse at gmail.com wrote:
> From: Jerome Glisse <jglisse at redhat.com>
> 
> Virtual address need to be fenced to know when we can safely remove it.
> This patch also properly clear the pagetable. Previously it was
> serouisly broken.
> 
> v2: For to update pagetable when unbinding bo (don't bailout if
>     bo_va->valid is true).
> 
> This version is for stable 3.5 only.

Why?