Re: [PATCH] drm/mediatek: update cursors by using async atomic update

[CK Hu <ck.hu@mediatek.com>]

Hi, Bibby:

On Fri, 2019-10-25 at 13:38 +0800, Bibby Hsieh wrote:
> Support to async updates of cursors by using the new atomic
> interface for that.
> 
> Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c  | 32 +++++++++++++++++
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.h  |  3 ++
>  drivers/gpu/drm/mediatek/mtk_drm_plane.c | 44 ++++++++++++++++++++++++
>  3 files changed, 79 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index b07dc9b59ca3..3c96178bd559 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -395,6 +395,38 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  	}
>  }
>  
> +void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,
> +				struct drm_plane_state *new_state)
> +{
> +	struct mtk_drm_private *priv = crtc->dev->dev_private;
> +	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> +	const struct drm_plane_helper_funcs *plane_helper_funcs =
> +			plane->helper_private;
> +	int i;
> +
> +	if (!mtk_crtc->enabled)
> +		return;
> +
> +	plane_helper_funcs->atomic_update(plane, new_state);

Why do you not call mtk_plane_atomic_update() directly?

> +
> +	for (i = 0; i < mtk_crtc->layer_nr; i++) {
> +		struct drm_plane *plane = &mtk_crtc->planes[i];
> +		struct mtk_plane_state *plane_state;
> +
> +		plane_state = to_mtk_plane_state(plane->state);
> +		if (plane_state->pending.dirty) {
> +			plane_state->pending.config = true;
> +			plane_state->pending.dirty = false;
> +		}
> +	}
> +	mtk_crtc->pending_planes = true;
> +	if (priv->data->shadow_register) {
> +		mtk_disp_mutex_acquire(mtk_crtc->mutex);
> +		mtk_crtc_ddp_config(crtc);
> +		mtk_disp_mutex_release(mtk_crtc->mutex);
> +	}

This part is the same as the part in mtk_drm_crtc_atomic_flush. Separate
the common part to an independent function.

Regards,
CK

> +}
> +
>  static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc,
>  				       struct drm_crtc_state *old_state)
>  {
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> index fcc134eb00c9..e65d58db201d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -20,4 +20,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>  			const enum mtk_ddp_comp_id *path,
>  			unsigned int path_len);
>  
> +void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,
> +				struct drm_plane_state *plane_state);
> +
>  #endif /* MTK_DRM_CRTC_H */
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index 584a9ecadce6..f0e91ecb3b4c 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -7,6 +7,7 @@
>  #include <drm/drm_atomic.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_fourcc.h>
> +#include <drm/drm_atomic_uapi.h>
>  #include <drm/drm_plane_helper.h>
>  #include <drm/drm_gem_framebuffer_helper.h>
>  
> @@ -70,6 +71,47 @@ static void mtk_drm_plane_destroy_state(struct drm_plane *plane,
>  	kfree(to_mtk_plane_state(state));
>  }
>  
> +static int mtk_plane_atomic_async_check(struct drm_plane *plane,
> +					struct drm_plane_state *state)
> +{
> +	struct drm_crtc_state *crtc_state;
> +
> +	if (plane != state->crtc->cursor)
> +		return -EINVAL;
> +
> +	if (!plane->state)
> +		return -EINVAL;
> +
> +	if (!plane->state->fb)
> +		return -EINVAL;
> +
> +	if (state->state)
> +		crtc_state = drm_atomic_get_existing_crtc_state(state->state,
> +								state->crtc);
> +	else /* Special case for asynchronous cursor updates. */
> +		crtc_state = state->crtc->state;
> +
> +	return drm_atomic_helper_check_plane_state(plane->state, crtc_state,
> +						   DRM_PLANE_HELPER_NO_SCALING,
> +						   DRM_PLANE_HELPER_NO_SCALING,
> +						   true, true);
> +}
> +
> +static void mtk_plane_atomic_async_update(struct drm_plane *plane,
> +					  struct drm_plane_state *new_state)
> +{
> +	plane->state->crtc_x = new_state->crtc_x;
> +	plane->state->crtc_y = new_state->crtc_y;
> +	plane->state->crtc_h = new_state->crtc_h;
> +	plane->state->crtc_w = new_state->crtc_w;
> +	plane->state->src_x = new_state->src_x;
> +	plane->state->src_y = new_state->src_y;
> +	plane->state->src_h = new_state->src_h;
> +	plane->state->src_w = new_state->src_w;
> +
> +	mtk_drm_crtc_cursor_update(new_state->crtc, plane, new_state);
> +}
> +
>  static const struct drm_plane_funcs mtk_plane_funcs = {
>  	.update_plane = drm_atomic_helper_update_plane,
>  	.disable_plane = drm_atomic_helper_disable_plane,
> @@ -151,6 +193,8 @@ static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = {
>  	.atomic_check = mtk_plane_atomic_check,
>  	.atomic_update = mtk_plane_atomic_update,
>  	.atomic_disable = mtk_plane_atomic_disable,
> +	.atomic_async_update = mtk_plane_atomic_async_update,
> +	.atomic_async_check = mtk_plane_atomic_async_check,
>  };
>  
>  int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,