Re: [PATCH 3/5] drm: shmobile: Switch to drm_crtc_init_with_planes()

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Laurent,

Thanks for your comments!

On Wed, Apr 5, 2023 at 5:59 AM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> On Fri, Mar 31, 2023 at 04:48:09PM +0200, Geert Uytterhoeven wrote:
> > The SH-Mobile DRM driver uses the legacy drm_crtc_init(), which
> > advertizes only the formats in safe_modeset_formats[] (XR24 and AR24) as
> > being supported.
> >
> > Switch to drm_crtc_init_with_planes(), and advertize all supported
> > (A)RGB modes, so we can use RGB565 as the default mode for the console.
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

> > --- a/drivers/gpu/drm/shmobile/shmob_drm_crtc.c
> > +++ b/drivers/gpu/drm/shmobile/shmob_drm_crtc.c
> > @@ -18,6 +18,7 @@
> >  #include <drm/drm_gem_dma_helper.h>
> >  #include <drm/drm_modeset_helper.h>
> >  #include <drm/drm_modeset_helper_vtables.h>
> > +#include <drm/drm_plane_helper.h>
> >  #include <drm/drm_probe_helper.h>
> >  #include <drm/drm_simple_kms_helper.h>
> >  #include <drm/drm_vblank.h>
> > @@ -478,16 +479,41 @@ static const struct drm_crtc_funcs crtc_funcs = {
> >       .disable_vblank = shmob_drm_disable_vblank,
> >  };
> >
> > +static const uint32_t modeset_formats[] = {
> > +     DRM_FORMAT_RGB565,
> > +     DRM_FORMAT_RGB888,
> > +     DRM_FORMAT_ARGB8888,
> > +     DRM_FORMAT_XRGB8888,
> > +};
> > +
> > +static const struct drm_plane_funcs primary_plane_funcs = {
> > +     DRM_PLANE_NON_ATOMIC_FUNCS,
> > +};
> > +
> >  int shmob_drm_crtc_create(struct shmob_drm_device *sdev)
> >  {
> >       struct drm_crtc *crtc = &sdev->crtc.crtc;
> > +     struct drm_plane *primary;
> >       int ret;
> >
> >       sdev->crtc.dpms = DRM_MODE_DPMS_OFF;
> >
> > -     ret = drm_crtc_init(sdev->ddev, crtc, &crtc_funcs);
> > -     if (ret < 0)
> > +     primary = __drm_universal_plane_alloc(sdev->ddev, sizeof(*primary), 0,
> > +                                           0, &primary_plane_funcs,
> > +                                           modeset_formats,
> > +                                           ARRAY_SIZE(modeset_formats),
> > +                                           NULL, DRM_PLANE_TYPE_PRIMARY,
> > +                                           NULL);
> > +     if (IS_ERR(primary))
> > +             return PTR_ERR(primary);
>
> This seems like a bit of a hack to me. Why don't you use the planes

I'm following what Thomas did in the nouveau driver....

> created by shmob_drm_plane_create() instead of allocating a new one ?

Is that possible? shmob_drm_plane_create() creates overlay planes,
while this is for the primary plane.

>
> > +
> > +     ret = drm_crtc_init_with_planes(sdev->ddev, crtc, primary, NULL,
> > +                                     &crtc_funcs, NULL);
> > +     if (ret < 0) {
> > +             drm_plane_cleanup(primary);
> > +             kfree(primary);
> >               return ret;
> > +     }
> >
> >       drm_crtc_helper_add(crtc, &crtc_helper_funcs);

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