On Thu, Jul 18, 2024 at 4:25 PM AngeloGioacchino Del Regno
<angelogioacchino.delregno@xxxxxxxxxxxxx> wrote:
>
> MediaTek SoCs support multiple planes, one of which is the primary
> and all the others are overlays (and CURSOR is the last overlay).
>
> In all currently supported SoCs, the Z order of the overlays can't
> be changed with any fast muxing action, and can only be changed by
> swapping the contents of the entire register set of one overlay
> with the other to internally reorder the layer properties, which
> is indeed feasible, but probably more expensive than desired.
>
> Declare the Z position for all planes with an immutable property
> at least for now, so that the userspace can take its decisions
> accordingly.
>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Fei Shao <fshao@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_crtc.c | 2 +-
> drivers/gpu/drm/mediatek/mtk_plane.c | 18 +++++++++++++++++-
> drivers/gpu/drm/mediatek/mtk_plane.h | 3 +--
> 3 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_crtc.c b/drivers/gpu/drm/mediatek/mtk_crtc.c
> index 072b2fdae87b..327214721b4d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_crtc.c
> @@ -874,7 +874,7 @@ static int mtk_crtc_init_comp_planes(struct drm_device *drm_dev,
> mtk_crtc_plane_type(mtk_crtc->layer_nr, num_planes),
> mtk_ddp_comp_supported_rotations(comp),
> mtk_ddp_comp_get_formats(comp),
> - mtk_ddp_comp_get_num_formats(comp));
> + mtk_ddp_comp_get_num_formats(comp), i);
> if (ret)
> return ret;
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_plane.c b/drivers/gpu/drm/mediatek/mtk_plane.c
> index 5bf757a3ef20..7d2cb4e0fafa 100644
> --- a/drivers/gpu/drm/mediatek/mtk_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_plane.c
> @@ -321,7 +321,7 @@ static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
> int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
> unsigned long possible_crtcs, enum drm_plane_type type,
> unsigned int supported_rotations, const u32 *formats,
> - size_t num_formats)
> + size_t num_formats, unsigned int plane_idx)
> {
> int err;
>
> @@ -338,6 +338,22 @@ int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
> return err;
> }
>
> + /*
> + * The hardware does not support repositioning planes by muxing: their
> + * Z-position is infact fixed and the only way to change the actual
> + * order is to swap the contents of the entire register set of one
> + * overlay with another, which may be more expensive than desired.
> + *
> + * With no repositioning, the caller of this function guarantees that
> + * the plane_idx is correct. This means that, for example, the PRIMARY
> + * plane fed to this function will always have plane_idx zero.
> + */
> + err = drm_plane_create_zpos_immutable_property(plane, plane_idx);
> + if (err) {
> + DRM_ERROR("Failed to create zpos property for plane %u\n", plane_idx);
> + return err;
> + }
> +
> if (supported_rotations) {
> err = drm_plane_create_rotation_property(plane,
> DRM_MODE_ROTATE_0,
> diff --git a/drivers/gpu/drm/mediatek/mtk_plane.h b/drivers/gpu/drm/mediatek/mtk_plane.h
> index 231bb7aac947..5b177eac67b7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_plane.h
> +++ b/drivers/gpu/drm/mediatek/mtk_plane.h
> @@ -49,6 +49,5 @@ to_mtk_plane_state(struct drm_plane_state *state)
> int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
> unsigned long possible_crtcs, enum drm_plane_type type,
> unsigned int supported_rotations, const u32 *formats,
> - size_t num_formats);
> -
> + size_t num_formats, unsigned int plane_idx);
> #endif
> --
> 2.45.2
>
>
