[PATCH 6/8] drm/amd/display: Set DC options from modifiers.

[Daniel Vetter]

On Mon, Aug 10, 2020 at 4:13 PM Bas Nieuwenhuizen
<bas at basnieuwenhuizen.nl> wrote:
>
> On Mon, Aug 10, 2020 at 3:09 PM Daniel Vetter <daniel at ffwll.ch> wrote:
> >
> > On Mon, Aug 10, 2020 at 02:49:00PM +0200, Michel Dänzer wrote:
> > > On 2020-08-10 2:28 p.m., Daniel Vetter wrote:
> > > >
> > > > Ok just learned that amdgpu hat set/get_tiling, so I'm upgrading my idea
> > > > here to a very strong recommendation, i.e. please do this except if
> > > > there's and amd ddx which somehow wants to change tiling mode while a fb
> > > > exists, and expects this to propagate.
> > > >
> > > > In i915 we even disallow the set_tiling ioctl with an error if an fb
> > > > exists, just to make sure userspace behaves. Even if userspace uses
> > > > set_tiling, this way we can at least enforce the same semantics of "client
> > > > can't pull compositor over the table with a set_tiling at the wrong time"
> > > > of modifiers.
> > >
> > > FWIW, xf86-video-amdgpu doesn't have any code to set the tiling
> > > metadata, only Mesa and presumably AMD's Vulkan/OpenGL UMDs do.
> >
> > Ah right you do everything with glamour, so this should never show up as a
> > problem.
>
> I think it is a good idea to do so, but cannot do it completely in
> this series as we don't define modifiers for GFX6-GFX8 GPU generations
> yet. (wanted to leave these out for a bit to reduce the scope for the
> initial version)

Hm right, that makes it a bit awkward.

> That said, there is a series that captures the tiling flags on FB
> creation: https://patchwork.freedesktop.org/series/80109/

Yeah, but it only pushes it down into the state objects. Good first
step, what I'm proposing is to push it all the way into addfb/struct
drm_framebuffer. Since drm_framebuffer is also an invariant thing it
makes the most sense to keep that there. I'm also discussing with
Nicholas about what would be the ideal end state.

But yeah maybe one thing at time.
-Daniel

>
> > -Daniel
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch
> > _______________________________________________
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> > amd-gfx at lists.freedesktop.org
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch