On 2023-09-25 15:49, Melissa Wen wrote:
> Add 3D LUT property for plane color transformations using a 3D lookup
> table. 3D LUT allows for highly accurate and complex color
> transformations and is suitable to adjust the balance between color
> channels. It's also more complex to manage and require more
> computational resources. Since a 3D LUT has a limited number of entries
> in each dimension we want to use them in an optimal fashion. This means
> using the 3D LUT in a colorspace that is optimized for human vision,
> such as sRGB, PQ, or another non-linear space. Therefore, userpace may
> need one 1D LUT (shaper) before it to delinearize content and another 1D
> LUT after 3D LUT (blend) to linearize content again for blending. The
> next patches add these 1D LUTs to the plane color mgmt pipeline.
>
> v3:
> - improve commit message about 3D LUT
> - describe the 3D LUT entries and size (Harry)
>
> Signed-off-by: Melissa Wen <m...@igalia.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 17 ++++++++++++++
> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 9 ++++++++
> .../amd/display/amdgpu_dm/amdgpu_dm_color.c | 14 +++++++++++
> .../amd/display/amdgpu_dm/amdgpu_dm_plane.c | 23 +++++++++++++++++++
> 4 files changed, 63 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> index 66bae0eed80c..1b5f25989f7f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> @@ -363,6 +363,23 @@ struct amdgpu_mode_info {
> * @plane_hdr_mult_property:
> */
> struct drm_property *plane_hdr_mult_property;
> + /**
> + * @plane_lut3d_property: Plane property for color transformation using
> + * a 3D LUT (pre-blending), a three-dimensional array where each
> + * element is an RGB triplet. Each dimension has a size of the cubed
> + * root of lut3d_size. The array contains samples from the approximated
> + * function. On AMD, values between samples are estimated by
> + * tetrahedral interpolation. The array is accessed with three indices,
> + * one for each input dimension (color channel), blue being the
> + * outermost dimension, red the innermost.
> + */
> + struct drm_property *plane_lut3d_property;
> + /**
> + * @plane_degamma_lut_size_property: Plane property to define the max
> + * size of 3D LUT as supported by the driver (read-only). The max size
> + * is the max size of one dimension cubed.
> + */
I've been thinking about this some more and don't particulary
like that we're reporting the size as the dimension cubed, e.g.,
4913 (17^3) instead of 17. This works for an AMD private API
(and I'm okay with keeping it as-is if changing it is a lot of
effort at this point) but in a generic API it would be a source
of bugs or undefined behavior if a driver mistakenly reported
a size that doesn't have an even cubed root.
Reporting the size of a single dimension (e.g., 17 in the case
of the current AMD driver) would be clearer.
Could we still change that?
Harry
> + struct drm_property *plane_lut3d_size_property;
> };
>
> #define AMDGPU_MAX_BL_LEVEL 0xFF
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> index 7ca594c7dfbe..dbd36fc24eca 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -773,6 +773,11 @@ struct dm_plane_state {
> * S31.32 sign-magnitude.
> */
> __u64 hdr_mult;
> + /**
> + * @lut3d: 3D lookup table blob. The blob (if not NULL) is an array of
> + * &struct drm_color_lut.
> + */
> + struct drm_property_blob *lut3d;
> };
>
> struct dm_crtc_state {
> @@ -858,6 +863,10 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector
> *connector,
>
> void amdgpu_dm_trigger_timing_sync(struct drm_device *dev);
>
> +/* 3D LUT max size is 17x17x17 */
> +#define MAX_COLOR_3DLUT_ENTRIES 4913
> +#define MAX_COLOR_3DLUT_BITDEPTH 12
> +/* 1D LUT size */
> #define MAX_COLOR_LUT_ENTRIES 4096
> /* Legacy gamm LUT users such as X doesn't like large LUT sizes */
> #define MAX_COLOR_LEGACY_LUT_ENTRIES 256
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> index f274909c0c7e..e2f3f2099cac 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c
> @@ -207,6 +207,20 @@ amdgpu_dm_create_color_properties(struct amdgpu_device
> *adev)
> return -ENOMEM;
> adev->mode_info.plane_hdr_mult_property = prop;
>
> + prop = drm_property_create(adev_to_drm(adev),
> + DRM_MODE_PROP_BLOB,
> + "AMD_PLANE_LUT3D", 0);
> + if (!prop)
> + return -ENOMEM;
> + adev->mode_info.plane_lut3d_property = prop;
> +
> + prop = drm_property_create_range(adev_to_drm(adev),
> + DRM_MODE_PROP_IMMUTABLE,
> + "AMD_PLANE_LUT3D_SIZE", 0, UINT_MAX);
> + if (!prop)
> + return -ENOMEM;
> + adev->mode_info.plane_lut3d_size_property = prop;
> +
> return 0;
> }
> #endif
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> index b66da6b76f5c..56f9109ecf60 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c
> @@ -1361,6 +1361,8 @@ dm_drm_plane_duplicate_state(struct drm_plane *plane)
>
> if (dm_plane_state->degamma_lut)
> drm_property_blob_get(dm_plane_state->degamma_lut);
> + if (dm_plane_state->lut3d)
> + drm_property_blob_get(dm_plane_state->lut3d);
>
> dm_plane_state->degamma_tf = old_dm_plane_state->degamma_tf;
> dm_plane_state->hdr_mult = old_dm_plane_state->hdr_mult;
> @@ -1434,6 +1436,8 @@ static void dm_drm_plane_destroy_state(struct drm_plane
> *plane,
>
> if (dm_plane_state->degamma_lut)
> drm_property_blob_put(dm_plane_state->degamma_lut);
> + if (dm_plane_state->lut3d)
> + drm_property_blob_put(dm_plane_state->lut3d);
>
> if (dm_plane_state->dc_state)
> dc_plane_state_release(dm_plane_state->dc_state);
> @@ -1464,6 +1468,14 @@ dm_atomic_plane_attach_color_mgmt_properties(struct
> amdgpu_display_manager *dm,
> drm_object_attach_property(&plane->base,
> dm->adev->mode_info.plane_hdr_mult_property,
> AMDGPU_HDR_MULT_DEFAULT);
> +
> + if (dpp_color_caps.hw_3d_lut) {
> + drm_object_attach_property(&plane->base,
> + mode_info.plane_lut3d_property, 0);
> + drm_object_attach_property(&plane->base,
> + mode_info.plane_lut3d_size_property,
> + MAX_COLOR_3DLUT_ENTRIES);
> + }
> }
>
> static int
> @@ -1495,6 +1507,14 @@ dm_atomic_plane_set_property(struct drm_plane *plane,
> dm_plane_state->hdr_mult = val;
> dm_plane_state->base.color_mgmt_changed = 1;
> }
> + } else if (property == adev->mode_info.plane_lut3d_property) {
> + ret = drm_property_replace_blob_from_id(plane->dev,
> + &dm_plane_state->lut3d,
> + val, -1,
> + sizeof(struct
> drm_color_lut),
> + &replaced);
> + dm_plane_state->base.color_mgmt_changed |= replaced;
> + return ret;
> } else {
> drm_dbg_atomic(plane->dev,
> "[PLANE:%d:%s] unknown property [PROP:%d:%s]]\n",
> @@ -1522,6 +1542,9 @@ dm_atomic_plane_get_property(struct drm_plane *plane,
> *val = dm_plane_state->degamma_tf;
> } else if (property == adev->mode_info.plane_hdr_mult_property) {
> *val = dm_plane_state->hdr_mult;
> + } else if (property == adev->mode_info.plane_lut3d_property) {
> + *val = (dm_plane_state->lut3d) ?
> + dm_plane_state->lut3d->base.id : 0;
> } else {
> return -EINVAL;
> }
