[Intel-gfx] [PATCH 2/2] drm/i915: Fail addfb ioctl if color and CCS buffers overlap

[Daniel Stone]

Hi Ville,

On 4 September 2017 at 17:37, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> On Thu, Aug 31, 2017 at 04:52:15PM -0300, Gabriel Krisman Bertazi wrote:
>> With this patch the new testcase igt at kms_ccs@pipe-X-invalid-ccs-offset
>> succeeds.
>
> I don't think we actually want to reject overlap. I had a patch for that
> years ago, but I decided to drop it because people might want to
> interleave the planes in some interesting ways. Making the overlap
> check accurate enough to allow that would be to total overkill. So IMO
> it's perfectly fine to let the user shoot himself in the foot if they
> mess up the offsets.

Is that actually supported by any hardware renderer? If not, maybe the
check should only be enabled for generations who support it.

Cheers,
Daniel