Re: [RFC PATCH 07/40] drm/amd/display: add CRTC gamma TF to driver-private props

From: Harry Wentland
Date: Mon May 08 2023 - 17:25:30 EST



On 4/23/23 10:10, Melissa Wen wrote:
> From: Joshua Ashton <joshua@xxxxxxxxx>
>
> Add predefined transfer function property to DRM CRTC gamma to convert
> to wire encoding with or without gamma LUT.
>

Are all these new CRTC properties used by gamescope? I would be reluctant
to merge them if they're currently not needed.

> Co-developed-by: Melissa Wen <mwen@xxxxxxxxxx>
> Signed-off-by: Melissa Wen <mwen@xxxxxxxxxx>
> Signed-off-by: Joshua Ashton <joshua@xxxxxxxxx>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 22 ++++++++++++++++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 4 ++++
> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h | 23 +++++++++++++++++++
> .../amd/display/amdgpu_dm/amdgpu_dm_crtc.c | 13 +++++++++++
> 4 files changed, 62 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> index 2abe5fe87c10..1913903cab88 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> @@ -1248,6 +1248,19 @@ amdgpu_display_user_framebuffer_create(struct drm_device *dev,
> }
>
> #ifdef CONFIG_STEAM_DECK
> +static const struct drm_prop_enum_list drm_transfer_function_enum_list[] = {
> + { DRM_TRANSFER_FUNCTION_DEFAULT, "Default" },
> + { DRM_TRANSFER_FUNCTION_SRGB, "sRGB" },
> + { DRM_TRANSFER_FUNCTION_BT709, "BT.709" },
> + { DRM_TRANSFER_FUNCTION_PQ, "PQ (Perceptual Quantizer)" },
> + { DRM_TRANSFER_FUNCTION_LINEAR, "Linear" },
> + { DRM_TRANSFER_FUNCTION_UNITY, "Unity" },
> + { DRM_TRANSFER_FUNCTION_HLG, "HLG (Hybrid Log Gamma)" },
> + { DRM_TRANSFER_FUNCTION_GAMMA22, "Gamma 2.2" },
> + { DRM_TRANSFER_FUNCTION_GAMMA24, "Gamma 2.4" },
> + { DRM_TRANSFER_FUNCTION_GAMMA26, "Gamma 2.6" },
> +};
> +

Would it be better to prefix things with AMD_/amd_ to avoid confusion? On the other
hand, these will likely just move into DRM core once we get the generic color uAPI.

Harry

> static int
> amdgpu_display_create_color_properties(struct amdgpu_device *adev)
> {
> @@ -1281,6 +1294,15 @@ amdgpu_display_create_color_properties(struct amdgpu_device *adev)
> return -ENOMEM;
> adev->mode_info.lut3d_size_property = prop;
>
> + prop = drm_property_create_enum(adev_to_drm(adev),
> + DRM_MODE_PROP_ENUM,
> + "GAMMA_TF",
> + drm_transfer_function_enum_list,
> + ARRAY_SIZE(drm_transfer_function_enum_list));
> + if (!prop)
> + return -ENOMEM;
> + adev->mode_info.gamma_tf_property = prop;
> +
> return 0;
> }
> #endif
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> index 205fa4f5bea7..76337e18c728 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> @@ -368,6 +368,10 @@ struct amdgpu_mode_info {
> * LUT as supported by the driver (read-only).
> */
> struct drm_property *lut3d_size_property;
> + /**
> + * @gamma_tf_property: Transfer function for CRTC regamma.
> + */
> + struct drm_property *gamma_tf_property;
> #endif
> };
>
> 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 09c3e1858b56..1e90a2dd445e 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -699,6 +699,23 @@ static inline void amdgpu_dm_set_mst_status(uint8_t *status,
>
> extern const struct amdgpu_ip_block_version dm_ip_block;
>
> +#ifdef CONFIG_STEAM_DECK
> +enum drm_transfer_function {
> + DRM_TRANSFER_FUNCTION_DEFAULT,
> +
> + DRM_TRANSFER_FUNCTION_SRGB,
> + DRM_TRANSFER_FUNCTION_BT709,
> + DRM_TRANSFER_FUNCTION_PQ,
> + DRM_TRANSFER_FUNCTION_LINEAR,
> + DRM_TRANSFER_FUNCTION_UNITY,
> + DRM_TRANSFER_FUNCTION_HLG,
> + DRM_TRANSFER_FUNCTION_GAMMA22,
> + DRM_TRANSFER_FUNCTION_GAMMA24,
> + DRM_TRANSFER_FUNCTION_GAMMA26,
> + DRM_TRANSFER_FUNCTION_MAX,
> +};
> +#endif
> +
> struct dm_plane_state {
> struct drm_plane_state base;
> struct dc_plane_state *dc_state;
> @@ -751,6 +768,12 @@ struct dm_crtc_state {
> * &struct drm_color_lut.
> */
> struct drm_property_blob *lut3d;
> + /**
> + * @gamma_tf:
> + *
> + * Pre-defined transfer function for converting internal FB -> wire encoding.
> + */
> + enum drm_transfer_function gamma_tf;
> #endif
> };
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> index 0e1280228e6e..79324fbab1f1 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_crtc.c
> @@ -272,6 +272,7 @@ static struct drm_crtc_state *dm_crtc_duplicate_state(struct drm_crtc *crtc)
> #ifdef CONFIG_STEAM_DECK
> state->shaper_lut = cur->shaper_lut;
> state->lut3d = cur->lut3d;
> + state->gamma_tf = cur->gamma_tf;
>
> if (state->shaper_lut)
> drm_property_blob_get(state->shaper_lut);
> @@ -336,6 +337,11 @@ dm_crtc_additional_color_mgmt(struct drm_crtc *crtc)
> adev->mode_info.lut3d_size_property,
> MAX_COLOR_3DLUT_ENTRIES);
> }
> +
> + if(adev->dm.dc->caps.color.mpc.ogam_ram)
> + drm_object_attach_property(&crtc->base,
> + adev->mode_info.gamma_tf_property,
> + DRM_TRANSFER_FUNCTION_DEFAULT);
> }
>
> static int
> @@ -398,6 +404,11 @@ amdgpu_dm_atomic_crtc_set_property(struct drm_crtc *crtc,
> &replaced);
> acrtc_state->base.color_mgmt_changed |= replaced;
> return ret;
> + } else if (property == adev->mode_info.gamma_tf_property) {
> + if (acrtc_state->gamma_tf != val) {
> + acrtc_state->gamma_tf = val;
> + acrtc_state->base.color_mgmt_changed |= 1;
> + }
> } else {
> drm_dbg_atomic(crtc->dev,
> "[CRTC:%d:%s] unknown property [PROP:%d:%s]]\n",
> @@ -424,6 +435,8 @@ amdgpu_dm_atomic_crtc_get_property(struct drm_crtc *crtc,
> else if (property == adev->mode_info.lut3d_property)
> *val = (acrtc_state->lut3d) ?
> acrtc_state->lut3d->base.id : 0;
> + else if (property == adev->mode_info.gamma_tf_property)
> + *val = acrtc_state->gamma_tf;
> else
> return -EINVAL;
>