[PATCH v2 06/10] drm/display/dsc: split DSC 1.2 and DSC 1.1 (pre-SCR) parameters

Jani Nikula jani.nikula at linux.intel.com
Wed Mar 8 10:14:30 UTC 2023


On Tue, 07 Mar 2023, Dmitry Baryshkov <dmitry.baryshkov at linaro.org> wrote:
> The array of rc_parameters contains a mixture of parameters from DSC 1.1
> and DSC 1.2 standards. Split these tow configuration arrays in
> preparation to adding more configuration data.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>  drivers/gpu/drm/display/drm_dsc_helper.c  | 127 ++++++++++++++++++----
>  drivers/gpu/drm/i915/display/intel_vdsc.c |  10 +-
>  include/drm/display/drm_dsc_helper.h      |   7 +-
>  3 files changed, 119 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dsc_helper.c b/drivers/gpu/drm/display/drm_dsc_helper.c
> index acb93d4116e0..35b39f3109c4 100644
> --- a/drivers/gpu/drm/display/drm_dsc_helper.c
> +++ b/drivers/gpu/drm/display/drm_dsc_helper.c
> @@ -324,11 +324,81 @@ struct rc_parameters_data {
>  
>  #define DSC_BPP(bpp)	((bpp) << 4)
>  
> +static const struct rc_parameters_data rc_parameters_pre_scr[] = {
> +	{
> +		.bpp = DSC_BPP(8), .bpc = 8,
> +		{ 512, 12, 6144, 3, 12, 11, 11, {
> +			{ 0, 4, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> +			{ 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> +			{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 }, { 5, 12, -12 },
> +			{ 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> +			}
> +		}
> +	},
> +	{
> +		.bpp = DSC_BPP(8), .bpc = 10,
> +		{ 512, 12, 6144, 7, 16, 15, 15, {
> +			/*
> +			 * DSC model/pre-SCR-cfg has 8 for range_max_qp[0], however
> +			 * VESA DSC 1.1 Table E-5 sets it to 4.
> +			 */
> +			{ 0, 4, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
> +			{ 7, 11, -4 }, { 7, 11, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> +			{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> +			{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> +			}
> +		}
> +	},
> +	{
> +		.bpp = DSC_BPP(8), .bpc = 12,
> +		{ 512, 12, 6144, 11, 20, 19, 19, {
> +			{ 0, 12, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 9, 14, -2 },
> +			{ 11, 15, -4 }, { 11, 15, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> +			{ 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> +			{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> +			{ 21, 23, -12 }
> +			}
> +		}
> +	},
> +	{
> +		.bpp = DSC_BPP(12), .bpc = 8,
> +		{ 341, 15, 2048, 3, 12, 11, 11, {
> +			{ 0, 2, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> +			{ 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> +			{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 },
> +			{ 5, 12, -12 }, { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> +			}
> +		}
> +	},
> +	{
> +		.bpp = DSC_BPP(12), .bpc = 10,
> +		{ 341, 15, 2048, 7, 16, 15, 15, {
> +			{ 0, 2, 2 }, { 2, 5, 0 }, { 3, 7, 0 }, { 4, 8, -2 },
> +			{ 6, 9, -4 }, { 7, 10, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> +			{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> +			{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> +			}
> +		}
> +	},
> +	{
> +		.bpp = DSC_BPP(12), .bpc = 12,
> +		{ 341, 15, 2048, 11, 20, 19, 19, {
> +			{ 0, 6, 2 }, { 4, 9, 0 }, { 7, 11, 0 }, { 8, 12, -2 },
> +			{ 10, 13, -4 }, { 11, 14, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> +			{ 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> +			{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> +			{ 21, 23, -12 }
> +			}
> +		}
> +	},
> +	{ /* sentinel */ }
> +};
> +
>  /*
>   * Selected Rate Control Related Parameter Recommended Values
>   * from DSC_v1.11 spec & C Model release: DSC_model_20161212
>   */

The comment is no longer accurate, is it?

There are various ways to determine the parameters to use. There's even
an application note "VESA DSC v1.2a Guidance on Deriving DSC Rate
Control Parameters" that lists the options. They are all valid and
should "provide visually lossless quality".

Would it be simplest to always use the C model parameters in the tables
here, referencing the zip file name with date above each table? That
could at least be consistent, and drivers could override parameters
using other methods if they desire. And it would be easiest to review.

I'm having a hard time finding time to review all this in a timely
fashion. Would be good to try to get other folks to review the rest,
it's really not very i915 specific anyway. In the mean time I think
patches 1-5 are okay to merge via drm-misc.

BR,
Jani.

> -static const struct rc_parameters_data rc_parameters[] = {
> +static const struct rc_parameters_data rc_parameters_1_2_444[] = {
>  	{
>  		.bpp = DSC_BPP(6), .bpc = 8,
>  		{ 768, 15, 6144, 3, 13, 11, 11, {
> @@ -388,22 +458,18 @@ static const struct rc_parameters_data rc_parameters[] = {
>  		{ 512, 12, 6144, 3, 12, 11, 11, {
>  			{ 0, 4, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
>  			{ 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> -			{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 }, { 5, 12, -12 },
> -			{ 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> +			{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 10, -10 }, { 5, 11, -12 },
> +			{ 5, 11, -12 }, { 9, 12, -12 }, { 12, 13, -12 }
>  			}
>  		}
>  	},
>  	{
>  		.bpp = DSC_BPP(8), .bpc = 10,
>  		{ 512, 12, 6144, 7, 16, 15, 15, {
> -			/*
> -			 * DSC model/pre-SCR-cfg has 8 for range_max_qp[0], however
> -			 * VESA DSC 1.1 Table E-5 sets it to 4.
> -			 */
> -			{ 0, 4, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
> +			{ 0, 8, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
>  			{ 7, 11, -4 }, { 7, 11, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> -			{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> -			{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> +			{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 14, -10 }, { 9, 15, -12 },
> +			{ 9, 15, -12 }, { 13, 16, -12 }, { 16, 17, -12 }
>  			}
>  		}
>  	},
> @@ -412,9 +478,9 @@ static const struct rc_parameters_data rc_parameters[] = {
>  		{ 512, 12, 6144, 11, 20, 19, 19, {
>  			{ 0, 12, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 9, 14, -2 },
>  			{ 11, 15, -4 }, { 11, 15, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> -			{ 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> -			{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> -			{ 21, 23, -12 }
> +			{ 11, 17, -8 }, { 11, 18, -10 }, { 13, 18, -10 },
> +			{ 13, 19, -12 }, { 13, 19, -12 }, { 17, 20, -12 },
> +			{ 20, 21, -12 }
>  			}
>  		}
>  	},
> @@ -498,8 +564,8 @@ static const struct rc_parameters_data rc_parameters[] = {
>  		{ 341, 15, 2048, 3, 12, 11, 11, {
>  			{ 0, 2, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
>  			{ 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> -			{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 },
> -			{ 5, 12, -12 }, { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> +			{ 3, 8, -8 }, { 3, 9, -10 }, { 5, 9, -10 }, { 5, 9, -12 },
> +			{ 5, 9, -12 }, { 7, 10, -12 }, { 10, 11, -12 }
>  			}
>  		}
>  	},
> @@ -508,8 +574,8 @@ static const struct rc_parameters_data rc_parameters[] = {
>  		{ 341, 15, 2048, 7, 16, 15, 15, {
>  			{ 0, 2, 2 }, { 2, 5, 0 }, { 3, 7, 0 }, { 4, 8, -2 },
>  			{ 6, 9, -4 }, { 7, 10, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> -			{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> -			{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> +			{ 7, 12, -8 }, { 7, 13, -10 }, { 9, 13, -10 }, { 9, 13, -12 },
> +			{ 9, 13, -12 }, { 11, 14, -12 }, { 14, 15, -12 }
>  			}
>  		}
>  	},
> @@ -518,9 +584,9 @@ static const struct rc_parameters_data rc_parameters[] = {
>  		{ 341, 15, 2048, 11, 20, 19, 19, {
>  			{ 0, 6, 2 }, { 4, 9, 0 }, { 7, 11, 0 }, { 8, 12, -2 },
>  			{ 10, 13, -4 }, { 11, 14, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> -			{ 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> -			{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> -			{ 21, 23, -12 }
> +			{ 11, 16, -8 }, { 11, 17, -10 }, { 13, 17, -10 },
> +			{ 13, 17, -12 }, { 13, 17, -12 }, { 15, 18, -12 },
> +			{ 18, 19, -12 }
>  			}
>  		}
>  	},
> @@ -602,7 +668,8 @@ static const struct rc_parameters_data rc_parameters[] = {
>  	{ /* sentinel */ }
>  };
>  
> -static const struct rc_parameters *get_rc_params(u16 dsc_bpp,
> +static const struct rc_parameters *get_rc_params(const struct rc_parameters_data *rc_parameters,
> +						 u16 dsc_bpp,
>  						 u8 bits_per_component)
>  {
>  	int i;
> @@ -622,11 +689,13 @@ static const struct rc_parameters *get_rc_params(u16 dsc_bpp,
>   * function.
>   *
>   * @vdsc_cfg: DSC Configuration data partially filled by driver
> + * @kind: operating mode and standard to follow
>   *
>   * Return: 0 or -error code in case of an error
>   */
> -int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg)
> +int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg, enum drm_dsc_params_kind kind)
>  {
> +	const struct rc_parameters_data *data;
>  	const struct rc_parameters *rc_params;
>  	int i;
>  
> @@ -634,7 +703,19 @@ int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg)
>  			 !vdsc_cfg->bits_per_component))
>  		return -EINVAL;
>  
> -	rc_params = get_rc_params(vdsc_cfg->bits_per_pixel,
> +	switch (kind) {
> +	case DRM_DSC_1_2_444:
> +		data = rc_parameters_1_2_444;
> +		break;
> +	case DRM_DSC_1_1_PRE_SCR:
> +		data = rc_parameters_pre_scr;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	rc_params = get_rc_params(data,
> +				  vdsc_cfg->bits_per_pixel,
>  				  vdsc_cfg->bits_per_component);
>  	if (!rc_params)
>  		return -EINVAL;
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
> index 20a4c2f343fe..a4d1d2ba71bb 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> @@ -157,7 +157,15 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
>  	if (DISPLAY_VER(dev_priv) >= 13) {
>  		calculate_rc_params(vdsc_cfg);
>  	} else {
> -		ret = drm_dsc_setup_rc_params(vdsc_cfg);
> +		if ((compressed_bpp == 8 ||
> +		     compressed_bpp == 12) &&
> +		    (vdsc_cfg->bits_per_component == 8 ||
> +		     vdsc_cfg->bits_per_component == 10 ||
> +		     vdsc_cfg->bits_per_component == 12))
> +			ret = drm_dsc_setup_rc_params(vdsc_cfg, DRM_DSC_1_1_PRE_SCR);
> +		else
> +			ret = drm_dsc_setup_rc_params(vdsc_cfg, DRM_DSC_1_2_444);
> +
>  		if (ret)
>  			return ret;
>  
> diff --git a/include/drm/display/drm_dsc_helper.h b/include/drm/display/drm_dsc_helper.h
> index 1681791f65a5..c634bb2935d3 100644
> --- a/include/drm/display/drm_dsc_helper.h
> +++ b/include/drm/display/drm_dsc_helper.h
> @@ -10,12 +10,17 @@
>  
>  #include <drm/display/drm_dsc.h>
>  
> +enum drm_dsc_params_kind {
> +	DRM_DSC_1_2_444,
> +	DRM_DSC_1_1_PRE_SCR, /* legacy params from DSC 1.1 */
> +};
> +
>  void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header);
>  int drm_dsc_dp_rc_buffer_size(u8 rc_buffer_block_size, u8 rc_buffer_size);
>  void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_sdp,
>  			      const struct drm_dsc_config *dsc_cfg);
>  void drm_dsc_set_rc_buf_thresh(struct drm_dsc_config *vdsc_cfg);
> -int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg);
> +int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg, enum drm_dsc_params_kind kind);
>  int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg);
>  
>  #endif /* _DRM_DSC_HELPER_H_ */

-- 
Jani Nikula, Intel Open Source Graphics Center


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