[Intel-gfx] [PATCH 00/12] drm/i915: Fix up the CCS code

[Jani Nikula]

On Mon, 28 Aug 2017, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Mon, Aug 28, 2017 at 02:35:54PM +0100, Daniel Stone wrote:
>> Hi Daniel,
>> 
>> On 25 August 2017 at 18:17, Daniel Vetter <daniel at ffwll.ch> wrote:
>> > Which of these do we need to cherry-pick over to -next-fixes? There's no
>> > annotations about that. If the answer is "most" I'm leaning towards
>> > disabling CCS for 4.14, minimal set would be ideal (and first in the patch
>> > series).
>> 
>> My opinion below; tl;dr is that I don't think most of them are
>> super-critical. Ville obviously has a far stronger opinion than me on
>> the shape of the code, so I'm fine with this series, which seems to
>> mostly be a merge back of the delta between whatever Ville's latest
>> branch was, and whatever the last patchset Ben sent out was.
>> 
>> >> Ville Syrjälä (12):
>> >>   drm/i915: Treat fb->offsets[] as a raw byte offset instead of a linear
>> >>     offset
>> 
>> This should land into -fixes. I trust Ville that it has no UABI
>> impact, but seems like something to be very consistent on.
>
> It does change the uabi. That's the whole point. What was merged doesn't
> agree with what userspace wants. So this we want in definitely so that
> we don't end up exposing the wrong uabi in any released kernel.
>
>> 
>> >>   drm/i915: Skip fence alignemnt check for the CCS plane
>> 
>> Not sure if this is -fixes material really, just a cleanup?
>
> It makes the kernel less likely to reject the fb entirely. So
> without this userspace has to be rather careful where it places
> the aux surface. I would include this as well.
>
>> 
>> >>   drm/i915: Switch over to the LLC/eLLC hotspot avoidance hash mode for
>> >>     CCS
>> 
>> Not -fixes, performance optimisation.
>
> We hope. It does change the layout of the compressed data though so if
> our testcases try to generate compressed data with the CPU it'll not go
> well if the test assumes the wrong hash mode. I would include this as
> well so that we don't end up in any kind of a mess later when we try to
> change it.
>
> So the patches were more or less sorted in priority order, and we want
> at least 01,02 and maybe 03.

When you decide what to apply, please *please* add the appropriate
Fixes: tags for the ones you want to show up in v4.14.

BR,
Jani.


>
>> 
>> >>   drm/i915: Add a comment exlaining CCS hsub/vsub
>> 
>> Seems harmless to land to -fixes.
>> 
>> >>   drm/i915: Nuke a pointless unreachable()
>> 
>> Ditto.
>> 
>> >>   drm/i915: Add the missing Y/Yf modifiers for SKL+ sprites
>> 
>> Per my previous reply, NAK to landing at all, since DDB/WM allocation
>> seems too broken for it to work.
>> 
>> >>   drm/i915: Clean up the sprite modifier checks
>> 
>> Fine with this, but doesn't seem like -fixes material.
>> 
>> >>   drm/i915: Add CCS capability for sprites
>> 
>> NAK, same reason as Y/Yf.
>> 
>> >>   drm/i915: Allow up to 32KB stride on SKL+ "sprites"
>> 
>> Again doesn't seem like -fixes necessarily?
>> 
>> >>   drm: Fix modifiers_property kernel doc
>> 
>> Good for -fixes.
>> 
>> >>   drm: Check that the plane supports the request format+modifier combo
>> 
>> Good for core (not Intel) -fixes.
>> 
>> >>   drm/i915: Remove the pipe/plane ID checks from
>> >>     skl_check_ccs_aux_surface()
>> 
>> Seems fine but probably not -fixes material; land in Intel after a merge?
>> 
>> Cheers,
>> Daniel

-- 
Jani Nikula, Intel Open Source Technology Center