[PATCH] drm/rockchip: Require the YTR modifier for AFBC

[Daniel Stone]

Hi Sandy,

On Thu, 25 Feb 2021 at 02:17, Huang Jiachai <hjc at rock-chips.com> wrote:
>      RK3399 and px30 can support YTR afbc format[RGB only], there is an
> hidden control bit to control this.

Great, thanks for providing this information!

> Hi Alyssa,
>
>      Can you add the following patch to test on your platform? thanks.
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 99bdb5a2a185..0780ad46230a 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -105,7 +105,7 @@
>   #define AFBC_FMT_U8U8U8U8      0x5
>   #define AFBC_FMT_U8U8U8                0x4
>
> -#define AFBC_TILE_16x16                BIT(4)
> +#define AFBC_FMT_YTR           BIT(4)
>
>   /*
>    * The coefficients of the following matrix are all fixed points.
> @@ -952,7 +952,9 @@ static void vop_plane_atomic_update(struct drm_plane
> *plane,
>          if (rockchip_afbc(fb->modifier)) {
>                  int afbc_format =
> vop_convert_afbc_format(fb->format->format);
>
> -               VOP_AFBC_SET(vop, format, afbc_format | AFBC_TILE_16x16);
> +               if (fb->modifier & AFBC_FORMAT_MOD_YTR)
> +                       afbc_format |= AFBC_FMT_YTR;
> +               VOP_AFBC_SET(vop, format, afbc_format);
>                  VOP_AFBC_SET(vop, hreg_block_split, 0);
>                  VOP_AFBC_SET(vop, win_sel, VOP_WIN_TO_INDEX(vop_win));
>                  VOP_AFBC_SET(vop, hdr_ptr, dma_addr);
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> index 4a2099cb582e..48e131b88c23 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.h
> @@ -20,6 +20,7 @@
>   #define ROCKCHIP_AFBC_MOD \
>          DRM_FORMAT_MOD_ARM_AFBC( \
>                  AFBC_FORMAT_MOD_BLOCK_SIZE_16x16 | AFBC_FORMAT_MOD_SPARSE \
> +                       | AFBC_FORMAT_MOD_YTR \
>          )

Looks good - this will help us confirm. I think the complete patch
though would advertise both YTR and non-YTR modifiers: per Arm's
recommendation, it sounds like [AX]RGB8888 formats should only
advertise the non-YTR variant, and [AX]BGR8888 should advertise both
variants. Does that make sense?

Cheers,
Daniel