[igt-dev] [PATCH] lib/igt_fb: Support Tile Size for AMD non linear modifiers.

[Mark Yacoub]

friendly ping.

On Tue, Apr 13, 2021 at 12:02 PM Mark Yacoub <markyacoub at chromium.org> wrote:
>
> From: Mark Yacoub <markyacoub at google.com>
>
> Calculate the width and height of the tile on amdgpu when the modifier
> is not linear.
>
> Cc: bas at basnieuwenhuizen.nl
> Cc: daniel.vetter at ffwll.ch
> Signed-off-by: markyacoub at chromium.org
> ---
>  lib/igt_fb.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/lib/igt_fb.c b/lib/igt_fb.c
> index 4ded7e78..3d1fdae5 100644
> --- a/lib/igt_fb.c
> +++ b/lib/igt_fb.c
> @@ -396,6 +396,19 @@ void igt_get_fb_tile_size(int fd, uint64_t modifier, int fb_bpp,
>                 vc4_modifier_param = fourcc_mod_broadcom_param(modifier);
>                 modifier = fourcc_mod_broadcom_mod(modifier);
>         }
> +       // For all non-linear modifiers, AMD uses 64 KiB tiles
> +       else if (IS_AMD_FMT_MOD(modifier)) {
> +               igt_require_amdgpu(fd);
> +               const int bytes_per_pixel = fb_bpp / 8;
> +               const int format_log2 = log2(bytes_per_pixel);
> +               const int pixel_log2 = log2(64 * 1024) - format_log2;
> +               const int width_log2 = (pixel_log2 + 1) / 2;
> +               const int height_log2 = pixel_log2 - width_log2;
> +
> +               *width_ret = 1 << width_log2;
> +               *height_ret = 1 << height_log2;
> +               return;
> +       }
>
>         switch (modifier) {
>         case LOCAL_DRM_FORMAT_MOD_NONE:
> --
> 2.31.1.295.g9ea45b61b8-goog
>