[PATCH] drm/nv50-nvc0: work around an evo channel hang that some people see

[Andy Whitcroft]

On Fri, Aug 05, 2011 at 02:41:25PM -0500, Seth Forshee wrote:
> BugLink: http://bugs.launchpad.net/bugs/583760
> 
> SRU Justification
> 
> Impact: Mouse cursor disappears after some time of using the nouveau
> driver on a computer with NV50 graphics
> 
> Fix: Backport of upstream workaround that avoids using the last 32 bytes
> of the evo ring buffer.
> 
> Test case: Verified against natty on LP #583760.
> 
> Note that no one has stepped up to verify this patch on lucid or
> maverick. However, since the patch is simple and unlikely to cause
> regressions I'm submitting it for those releases as well.

Looks to do what is claimed.  Seems to only reduce the buffer size which
sounds safe also.  Seems targetted specifically to one device.  Looks
safe enough to me.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw