[PATCH] drm/mediatek: Ensure the cursor plane is on top of other overlays

[CK Hu]

Hi, Sean:

On Thu, 2020-01-30 at 14:24 -0500, Sean Paul wrote:
> From: Sean Paul <seanpaul at chromium.org>
> 
> Currently the cursor is placed on the first overlay plane, which means
> it will be at the bottom of the stack when the hw does the compositing
> with anything other than primary plane. Since mtk doesn't support plane
> zpos, change the cursor location to the top-most plane.
> 

Reviewed-by: CK Hu <ck.hu at mediatek.com>

> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 0dfcd1787e651..4ac76b9613926 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -689,11 +689,12 @@ static int mtk_drm_crtc_num_comp_planes(struct mtk_drm_crtc *mtk_crtc,
>  }
>  
>  static inline
> -enum drm_plane_type mtk_drm_crtc_plane_type(unsigned int plane_idx)
> +enum drm_plane_type mtk_drm_crtc_plane_type(unsigned int plane_idx,
> +					    unsigned int num_planes)
>  {
>  	if (plane_idx == 0)
>  		return DRM_PLANE_TYPE_PRIMARY;
> -	else if (plane_idx == 1)
> +	else if (plane_idx == (num_planes - 1))
>  		return DRM_PLANE_TYPE_CURSOR;
>  	else
>  		return DRM_PLANE_TYPE_OVERLAY;
> @@ -712,7 +713,8 @@ static int mtk_drm_crtc_init_comp_planes(struct drm_device *drm_dev,
>  		ret = mtk_plane_init(drm_dev,
>  				&mtk_crtc->planes[mtk_crtc->layer_nr],
>  				BIT(pipe),
> -				mtk_drm_crtc_plane_type(mtk_crtc->layer_nr),
> +				mtk_drm_crtc_plane_type(mtk_crtc->layer_nr,
> +							num_planes),
>  				mtk_ddp_comp_supported_rotations(comp));
>  		if (ret)
>  			return ret;