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

[Harry Wentland <harry.wentland@amd.com>]

On 4/23/23 10:10, Melissa Wen wrote:
> From: Joshua Ashton <joshua@froggi.es>
> 
> 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@igalia.com>
> Signed-off-by: Melissa Wen <mwen@igalia.com>
> Signed-off-by: Joshua Ashton <joshua@froggi.es>
> ---
>  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;
>