Re: [PATCH v2 13/15] drm/mediatek: use layer_nr function to get layer number to init plane

From: CK Hu
Date: Fri Aug 03 2018 - 01:33:42 EST


Hi, Stu:

On Fri, 2018-08-03 at 11:11 +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 | 26 ++++++++++++++++++--------
> drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 2 +-
> 2 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 4bf636e466f2..b4d3dfca4003 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[MAX_LAYER_NR];

For the RDMA crtc, there is only one plane but here allocate 4 planes. I
would like the array size is depend on layer_nr to prevent wasting
memory.

> + unsigned int layer_nr;
> bool pending_planes;
>
> void __iomem *config_regs;
> @@ -286,7 +287,7 @@ 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++) {
> + for (i = 0; i < mtk_crtc->layer_nr; i++) {
> struct drm_plane *plane = &mtk_crtc->planes[i];
> struct mtk_plane_state *plane_state;
>
> @@ -351,7 +352,7 @@ static void mtk_crtc_ddp_config(struct drm_crtc *crtc)
> }
>
> if (mtk_crtc->pending_planes) {
> - for (i = 0; i < OVL_LAYER_NR; i++) {
> + for (i = 0; i < mtk_crtc->layer_nr; i++) {
> struct drm_plane *plane = &mtk_crtc->planes[i];
> struct mtk_plane_state *plane_state;
>
> @@ -403,7 +404,7 @@ 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++) {
> + for (i = 0; i < mtk_crtc->layer_nr; i++) {
> struct drm_plane *plane = &mtk_crtc->planes[i];
> struct mtk_plane_state *plane_state;
>
> @@ -450,7 +451,7 @@ 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++) {
> + for (i = 0; i < mtk_crtc->layer_nr; i++) {
> struct drm_plane *plane = &mtk_crtc->planes[i];
> struct mtk_plane_state *plane_state;
>
> @@ -596,6 +597,9 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> goto unprepare;
> }
>
> + if (i == 0)
> + mtk_crtc->layer_nr = mtk_ddp_comp_layer_nr(comp);
> +
> if (i == 0 && (comp_id == DDP_COMPONENT_RDMA0 ||
> comp_id == DDP_COMPONENT_RDMA1 ||
> comp_id == DDP_COMPONENT_RDMA2)) {
> @@ -606,7 +610,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> mtk_crtc->ddp_comp[i] = comp;
> }
>
> - for (zpos = 0; zpos < OVL_LAYER_NR; zpos++) {
> + for (zpos = 0; zpos < mtk_crtc->layer_nr; zpos++) {
> type = (zpos == 0) ? DRM_PLANE_TYPE_PRIMARY :
> (zpos == 1) ? DRM_PLANE_TYPE_CURSOR :
> DRM_PLANE_TYPE_OVERLAY;
> @@ -616,8 +620,14 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> goto unprepare;
> }
>
> - ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
> - &mtk_crtc->planes[1], pipe);
> + if (mtk_crtc->layer_nr == 1) {
> + ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
> + NULL, pipe);
> + } else {
> + ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
> + &mtk_crtc->planes[1], pipe);
> + }

You could write as

ret = mtk_drm_crtc_init(drm_dev, mtk_crtc, &mtk_crtc->planes[0],
mtk_crtc->layer_nr > 1 ? &mtk_crtc->planes[1] : NULL, pipe);

Regards,
CK

> +
> 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..0399321b1414 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h
> @@ -18,7 +18,7 @@
> #include "mtk_drm_ddp_comp.h"
> #include "mtk_drm_plane.h"
>
> -#define OVL_LAYER_NR 4
> +#define MAX_LAYER_NR 4
> #define MTK_LUT_SIZE 512
> #define MTK_MAX_BPC 10
> #define MTK_MIN_BPC 3