Re: [PATCH v4 77/78] drm/vc4: drv: Support BCM2711

[Dave Stevenson]

Hi Maxime

On Wed, 8 Jul 2020 at 18:44, Maxime Ripard <maxime@xxxxxxxxxx> wrote:
>
> The BCM2711 has a reworked display pipeline, and the load tracker needs
> some adjustement to operate properly. Let's add a compatible for BCM2711

s/adjustement/adjustment

> and disable the load tracker until properly supported.
>
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/vc4/vc4_drv.c   |  1 +-
>  drivers/gpu/drm/vc4/vc4_drv.h   |  3 ++-
>  drivers/gpu/drm/vc4/vc4_kms.c   | 42 +++++++++++++++++++++++-----------
>  drivers/gpu/drm/vc4/vc4_plane.c |  5 ++++-
>  4 files changed, 38 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
> index 9567d1019212..f1a5fd5dab6f 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -372,6 +372,7 @@ static int vc4_platform_drm_remove(struct platform_device *pdev)
>  }
>
>  static const struct of_device_id vc4_of_match[] = {
> +       { .compatible = "brcm,bcm2711-vc5", },
>         { .compatible = "brcm,bcm2835-vc4", },
>         { .compatible = "brcm,cygnus-vc4", },
>         {},
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
> index 501a48a714d3..8c8d96b6289f 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.h
> +++ b/drivers/gpu/drm/vc4/vc4_drv.h
> @@ -200,6 +200,9 @@ struct vc4_dev {
>
>         int power_refcount;
>
> +       /* Set to true when the load tracker is supported. */
> +       bool load_tracker_available;
> +
>         /* Set to true when the load tracker is active. */
>         bool load_tracker_enabled;
>
> diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
> index 7c8a87339959..ae479f988666 100644
> --- a/drivers/gpu/drm/vc4/vc4_kms.c
> +++ b/drivers/gpu/drm/vc4/vc4_kms.c
> @@ -532,6 +532,9 @@ static int vc4_load_tracker_atomic_check(struct drm_atomic_state *state)
>         struct drm_plane *plane;
>         int i;
>
> +       if (!vc4->load_tracker_available)
> +               return 0;
> +
>         priv_state = drm_atomic_get_private_obj_state(state,
>                                                       &vc4->load_tracker);
>         if (IS_ERR(priv_state))
> @@ -681,10 +684,14 @@ int vc4_kms_load(struct drm_device *dev)
>         struct vc4_load_tracker_state *load_state;
>         int ret;
>
> -       /* Start with the load tracker enabled. Can be disabled through the
> -        * debugfs load_tracker file.
> -        */
> -       vc4->load_tracker_enabled = true;
> +       if (!of_device_is_compatible(dev->dev->of_node, "brcm,bcm2711-vc5")) {

Is it better to look up the compatible string, or pass something via
the .data element of the of_device_id table? Probably down to personal
preference?

> +               vc4->load_tracker_available = true;
> +
> +               /* Start with the load tracker enabled. Can be
> +                * disabled through the debugfs load_tracker file.
> +                */
> +               vc4->load_tracker_enabled = true;
> +       }
>
>         sema_init(&vc4->async_modeset, 1);
>
> @@ -698,8 +705,14 @@ int vc4_kms_load(struct drm_device *dev)
>                 return ret;
>         }
>
> -       dev->mode_config.max_width = 2048;
> -       dev->mode_config.max_height = 2048;
> +       if (of_device_is_compatible(dev->dev->of_node, "brcm,bcm2711-vc5")) {

We're making the same of_device_is_compatible call twice within
vc4_kms_load. Set a flag based on it and check that instead?

  Dave

> +               dev->mode_config.max_width = 7680;
> +               dev->mode_config.max_height = 7680;
> +       } else {
> +               dev->mode_config.max_width = 2048;
> +               dev->mode_config.max_height = 2048;
> +       }
> +
>         dev->mode_config.funcs = &vc4_mode_funcs;
>         dev->mode_config.preferred_depth = 24;
>         dev->mode_config.async_page_flip = true;
> @@ -714,14 +727,17 @@ int vc4_kms_load(struct drm_device *dev)
>         drm_atomic_private_obj_init(dev, &vc4->ctm_manager, &ctm_state->base,
>                                     &vc4_ctm_state_funcs);
>
> -       load_state = kzalloc(sizeof(*load_state), GFP_KERNEL);
> -       if (!load_state) {
> -               drm_atomic_private_obj_fini(&vc4->ctm_manager);
> -               return -ENOMEM;
> -       }
> +       if (vc4->load_tracker_available) {
> +               load_state = kzalloc(sizeof(*load_state), GFP_KERNEL);
> +               if (!load_state) {
> +                       drm_atomic_private_obj_fini(&vc4->ctm_manager);
> +                       return -ENOMEM;
> +               }
>
> -       drm_atomic_private_obj_init(dev, &vc4->load_tracker, &load_state->base,
> -                                   &vc4_load_tracker_state_funcs);
> +               drm_atomic_private_obj_init(dev, &vc4->load_tracker,
> +                                           &load_state->base,
> +                                           &vc4_load_tracker_state_funcs);
> +       }
>
>         drm_mode_config_reset(dev);
>
> diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
> index 1e38e603f83b..24d7e6db6fdd 100644
> --- a/drivers/gpu/drm/vc4/vc4_plane.c
> +++ b/drivers/gpu/drm/vc4/vc4_plane.c
> @@ -516,6 +516,11 @@ static void vc4_plane_calc_load(struct drm_plane_state *state)
>         struct vc4_plane_state *vc4_state;
>         struct drm_crtc_state *crtc_state;
>         unsigned int vscale_factor;
> +       struct vc4_dev *vc4;
> +
> +       vc4 = to_vc4_dev(state->plane->dev);
> +       if (!vc4->load_tracker_available)
> +               return;
>
>         vc4_state = to_vc4_plane_state(state);
>         crtc_state = drm_atomic_get_existing_crtc_state(state->state,
> --
> git-series 0.9.1