Re: [PATCH v3 11/13] drm/mediatek: use layer_nr function to get layer number to init plane

[CK Hu]

Hi, Stu:

On Mon, 2018-08-06 at 19:58 +0800, Stu Hsieh wrote:
> This patch use layer_nr function to get layer number to init plane
> 
> When plane init in crtc create,
> it use the number of OVL layer to init plane.
> That's OVL can read 4 memory address.
> 
> For mt2712 third ddp, it use RDMA to read memory.
> RDMA can read 1 memory address, so it just init one plane.
> 
> For compatibility, this patch use mtk_ddp_comp_layer_nr function
> to get layer number from their HW component in ddp for plane init.
> 
> Signed-off-by: Stu Hsieh <stu.hsieh@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 37 +++++++++++++++++++++------------
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.h |  1 -
>  2 files changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 2d6aa150a9ff..1a8685fbbf57 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -45,7 +45,8 @@ struct mtk_drm_crtc {
>  	bool				pending_needs_vblank;
>  	struct drm_pending_vblank_event	*event;
>  
> -	struct drm_plane		planes[OVL_LAYER_NR];
> +	struct drm_plane		**planes;

Why double pointer? This make things more complicated.
Single pointer is equal to array, so you need not to modify so many
place.

Regards,
CK

> +	unsigned int			layer_nr;
>  	bool				pending_planes;
>  
>  	void __iomem			*config_regs;
> @@ -286,8 +287,8 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
>  	}
>  
>  	/* Initially configure all planes */
> -	for (i = 0; i < OVL_LAYER_NR; i++) {
> -		struct drm_plane *plane = &mtk_crtc->planes[i];
> +	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);
> @@ -351,8 +352,8 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
>  	}
>  
>  	if (mtk_crtc->pending_planes) {
> -		for (i = 0; i < OVL_LAYER_NR; i++) {
> -			struct drm_plane *plane = &mtk_crtc->planes[i];
> +		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);
> @@ -403,8 +404,8 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
>  		return;
>  
>  	/* Set all pending plane state to disabled */
> -	for (i = 0; i < OVL_LAYER_NR; i++) {
> -		struct drm_plane *plane = &mtk_crtc->planes[i];
> +	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);
> @@ -450,8 +451,8 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
>  
>  	if (mtk_crtc->event)
>  		mtk_crtc->pending_needs_vblank = true;
> -	for (i = 0; i < OVL_LAYER_NR; i++) {
> -		struct drm_plane *plane = &mtk_crtc->planes[i];
> +	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);
> @@ -598,18 +599,28 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>  		mtk_crtc->ddp_comp[i] = comp;
>  	}
>  
> -	for (zpos = 0; zpos < OVL_LAYER_NR; zpos++) {
> +	mtk_crtc->layer_nr = mtk_ddp_comp_layer_nr(mtk_crtc->ddp_comp[0]);
> +	mtk_crtc->planes = devm_kmalloc_array(dev, mtk_crtc->layer_nr,
> +					      sizeof(*mtk_crtc->planes),
> +					      GFP_KERNEL);
> +
> +	for (zpos = 0; zpos < mtk_crtc->layer_nr; zpos++) {
> +		mtk_crtc->planes[zpos] = devm_kzalloc(dev,
> +						sizeof(*mtk_crtc->planes[zpos]),
> +						GFP_KERNEL);
> +
>  		type = (zpos == 0) ? DRM_PLANE_TYPE_PRIMARY :
>  				(zpos == 1) ? DRM_PLANE_TYPE_CURSOR :
>  						DRM_PLANE_TYPE_OVERLAY;
> -		ret = mtk_plane_init(drm_dev, &mtk_crtc->planes[zpos],
> +		ret = mtk_plane_init(drm_dev, mtk_crtc->planes[zpos],
>  				     BIT(pipe), type);
>  		if (ret)
>  			goto unprepare;
>  	}
>  
> -	ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
> -				&mtk_crtc->planes[1], pipe);
> +	ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, mtk_crtc->planes[0],
> +				mtk_crtc->layer_nr > 1 ? mtk_crtc->planes[1] :
> +				NULL, pipe);
>  	if (ret < 0)
>  		goto unprepare;
>  	drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> index 9d9410c67ae9..60bcc8aba8e3 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -18,7 +18,6 @@
>  #include "mtk_drm_ddp_comp.h"
>  #include "mtk_drm_plane.h"
>  
> -#define OVL_LAYER_NR	4
>  #define MTK_LUT_SIZE	512
>  #define MTK_MAX_BPC	10
>  #define MTK_MIN_BPC	3