Re: [PATCH] drm/radeon/si: Add support for CP DMA to CS checker for compute v2

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Aug 16, 2013 at 05:31:39PM -0700, Tom Stellard wrote:
> On Fri, Aug 16, 2013 at 03:34:09PM -0700, Greg KH wrote:
> > On Fri, Aug 16, 2013 at 05:47:39PM -0400, Tom Stellard wrote:
> > > From: Tom Stellard <thomas.stellard@amd.com>
> > > 
> > > Also add a new RADEON_INFO query to check that CP DMA packets are
> > > supported on the compute ring.
> > > 
> > > v2:
> > >   - Don't bump kms version, so this patch can be backported to stable
> > >     kernels.
> > 
> > Why is this for a stable kernel?  What reported problem does it fix?
> > 
> 
> CP DMA has been supported since the 3.8 kernel, but due to an oversight
> we forgot to teach the CS checker that the CP DMA packet was legal for
> the compute ring on Southern Islands GPUs.
> 
> This patch fixes a bug where the radeon driver will incorrectly reject a legal
> CP DMA packet from user space.  I would like to have the patch
> backported to stable so that we don't have to require Mesa users to use a
> bleeding edge kernel in order to take advantage of this feature which
> is already present in the stable kernels (3.8 and newer).

Then please put that in the changelog section of the patch, otherwise
people (like me), will ask these types of things :)

thanks,

greg k-h