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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Sun, 25 Jun 2023 10:58:17 +0200
Message-ID: <CAMuHMdWdeRODcAa26EKuvR3yca0hVqSUR6WBHEtr9+RBKyk_Ow@mail.gmail.com>
Subject: Re: [PATCH 24/39] drm: renesas: shmobile: Unify plane allocation
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Magnus Damm <magnus.damm@gmail.com>,
        dri-devel@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org
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Hi Laurent,

On Fri, Jun 23, 2023 at 8:50 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Fri, Jun 23, 2023 at 07:55:22PM +0200, Geert Uytterhoeven wrote:
> > On Fri, Jun 23, 2023 at 6:50 PM Laurent Pinchart wrote:
> > > On Thu, Jun 22, 2023 at 11:21:36AM +0200, Geert Uytterhoeven wrote:
> > > > Unify primary and overlay plane allocation:
> > > >   - Enhance shmob_drm_plane_create() so it can be used to create the
> > > >     primary plane, too,
> > > >   - Move overlay plane creation next to primary plane creation.
> > > >
> > > > As overlay plane index zero now means the primary plane, this requires
> > > > shifting all overlay plane indices by one.
> > >
> > > Do you use index zero to identify the primary plane just for
> > > shmob_drm_plane_create(), or somewhere else too ? If it's just to create
> > > the plane, you could instead pass the plane type to the function.
> >
> > Index zero is just used for the creation.
> > I guess this sort of goes together with my question below...
> >
> > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > > ---
> > > > Perhaps it would be better to not use dynamic allocation, but store
> > > > "struct drm_plane primary" and "struct shmob_drm_plane planes[5]" in
> > > > struct drm_shmob_device instead, like is done for the crtc and encoder?
> >
> > ... as embedding separate primary and planes[] would also get rid of
> > the need to adjust the plane indices when converting from logical to physical
> > overlay plane indices.
>
> Do they need to be embedded for that, or could you simple keep the index
> as it is ?

If the plane type would be passed explicitly, they would not need to be
embedded for that.

Then the question becomes: does it make sense to unify primary and
overlay plane handling?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds