[PATCH 05/10] drm/display/dsc: use flat array for rc_parameters lookup

Jani Nikula jani.nikula at linux.intel.com
Tue Feb 28 16:28:20 UTC 2023


On Tue, 28 Feb 2023, Dmitry Baryshkov <dmitry.baryshkov at linaro.org> wrote:
> Next commits are going to add support for additional RC parameter lookup
> tables. These tables are going to use different bpp/bpc combinations,
> thus it makes little sense to keep the 2d array for RC parameters.
> Switch to using the flat array.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>  drivers/gpu/drm/display/drm_dsc_helper.c | 188 +++++++++++------------
>  1 file changed, 88 insertions(+), 100 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dsc_helper.c b/drivers/gpu/drm/display/drm_dsc_helper.c
> index deaa84722bd4..a6d11f474656 100644
> --- a/drivers/gpu/drm/display/drm_dsc_helper.c
> +++ b/drivers/gpu/drm/display/drm_dsc_helper.c
> @@ -307,24 +307,6 @@ void drm_dsc_set_rc_buf_thresh(struct drm_dsc_config *vdsc_cfg)
>  }
>  EXPORT_SYMBOL(drm_dsc_set_rc_buf_thresh);
>  
> -enum ROW_INDEX_BPP {
> -	ROW_INDEX_6BPP = 0,
> -	ROW_INDEX_8BPP,
> -	ROW_INDEX_10BPP,
> -	ROW_INDEX_12BPP,
> -	ROW_INDEX_15BPP,
> -	MAX_ROW_INDEX
> -};
> -
> -enum COLUMN_INDEX_BPC {
> -	COLUMN_INDEX_8BPC = 0,
> -	COLUMN_INDEX_10BPC,
> -	COLUMN_INDEX_12BPC,
> -	COLUMN_INDEX_14BPC,
> -	COLUMN_INDEX_16BPC,
> -	MAX_COLUMN_INDEX
> -};
> -
>  struct rc_parameters {
>  	u16 initial_xmit_delay;
>  	u8 first_line_bpg_offset;
> @@ -336,12 +318,20 @@ struct rc_parameters {
>  	struct drm_dsc_rc_range_parameters rc_range_params[DSC_NUM_BUF_RANGES];
>  };
>  
> +struct rc_parameters_data {
> +	u8 bpp;
> +	u8 bpc;
> +	struct rc_parameters params;
> +};
> +
> +#define DSC_BPP(bpp)	((bpp) << 4)
> +
>  /*
>   * Selected Rate Control Related Parameter Recommended Values
>   * from DSC_v1.11 spec & C Model release: DSC_model_20161212
>   */
> -static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
> -{
> +static const struct rc_parameters_data rc_parameters[] = {
> +{ DSC_BPP(6), 8,

I was kind of hoping for a patch that would clean up the hideous
indentation in the tables. Please at least let's not add more with the
one space indent?

>  	/* 6BPP/8BPC */

With designated initializers I think we could just toss the comments
out.

	.bpp = DSC_BPP(6), .bpc = 8,

With that,

Reviewed-by: Jani Nikula <jani.nikula at intel.com>


>  	{ 768, 15, 6144, 3, 13, 11, 11, {
>  		{ 0, 4, 0 }, { 1, 6, -2 }, { 3, 8, -2 }, { 4, 8, -4 },
> @@ -349,7 +339,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 7, 11, -8 }, { 8, 12, -10 }, { 9, 12, -10 }, { 10, 12, -12 },
>  		{ 10, 12, -12 }, { 11, 12, -12 }, { 13, 14, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(6), 10,
>  	/* 6BPP/10BPC */
>  	{ 768, 15, 6144, 7, 17, 15, 15, {
>  		{ 0, 8, 0 }, { 3, 10, -2 }, { 7, 12, -2 }, { 8, 12, -4 },
> @@ -358,7 +350,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 14, 16, -12 }, { 14, 16, -12 }, { 15, 16, -12 },
>  		{ 17, 18, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(6), 12,
>  	/* 6BPP/12BPC */
>  	{ 768, 15, 6144, 11, 21, 19, 19, {
>  		{ 0, 12, 0 }, { 5, 14, -2 }, { 11, 16, -2 }, { 12, 16, -4 },
> @@ -367,7 +361,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 18, 20, -12 }, { 18, 20, -12 }, { 19, 20, -12 },
>  		{ 21, 22, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(6), 14,
>  	/* 6BPP/14BPC */
>  	{ 768, 15, 6144, 15, 25, 23, 23, {
>  		{ 0, 16, 0 }, { 7, 18, -2 }, { 15, 20, -2 }, { 16, 20, -4 },
> @@ -376,7 +372,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 22, 24, -12 }, { 22, 24, -12 }, { 23, 24, -12 },
>  		{ 25, 26, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(6), 16,
>  	/* 6BPP/16BPC */
>  	{ 768, 15, 6144, 19, 29, 27, 27, {
>  		{ 0, 20, 0 }, { 9, 22, -2 }, { 19, 24, -2 }, { 20, 24, -4 },
> @@ -385,9 +383,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 26, 28, -12 }, { 26, 28, -12 }, { 27, 28, -12 },
>  		{ 29, 30, -12 }
>  		}
> -	},
> +	}
>  },
> -{
> +{ DSC_BPP(8), 8,
>  	/* 8BPP/8BPC */
>  	{ 512, 12, 6144, 3, 12, 11, 11, {
>  		{ 0, 4, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> @@ -395,7 +393,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 }, { 5, 12, -12 },
>  		{ 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(8), 10,
>  	/* 8BPP/10BPC */
>  	{ 512, 12, 6144, 7, 16, 15, 15, {
>  		/*
> @@ -407,7 +407,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
>  		{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(8), 12,
>  	/* 8BPP/12BPC */
>  	{ 512, 12, 6144, 11, 20, 19, 19, {
>  		{ 0, 12, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 9, 14, -2 },
> @@ -416,7 +418,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
>  		{ 21, 23, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(8), 14,
>  	/* 8BPP/14BPC */
>  	{ 512, 12, 6144, 15, 24, 23, 23, {
>  		{ 0, 12, 2 }, { 5, 13, 0 }, { 11, 15, 0 }, { 12, 17, -2 },
> @@ -425,7 +429,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 17, 23, -12 }, { 17, 23, -12 }, { 21, 24, -12 },
>  		{ 24, 25, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(8), 16,
>  	/* 8BPP/16BPC */
>  	{ 512, 12, 6144, 19, 28, 27, 27, {
>  		{ 0, 12, 2 }, { 6, 14, 0 }, { 13, 17, 0 }, { 15, 20, -2 },
> @@ -434,9 +440,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 21, 27, -12 }, { 21, 27, -12 }, { 25, 28, -12 },
>  		{ 28, 29, -12 }
>  		}
> -	},
> +	}
>  },
> -{
> +{ DSC_BPP(10), 8,
>  	/* 10BPP/8BPC */
>  	{ 410, 15, 5632, 3, 12, 11, 11, {
>  		{ 0, 3, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 2, 6, -2 },
> @@ -444,7 +450,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 3, 9, -8 }, { 3, 9, -10 }, { 5, 10, -10 }, { 5, 10, -10 },
>  		{ 5, 11, -12 }, { 7, 11, -12 }, { 11, 12, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(10), 10,
>  	/* 10BPP/10BPC */
>  	{ 410, 15, 5632, 7, 16, 15, 15, {
>  		{ 0, 7, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 6, 10, -2 },
> @@ -452,7 +460,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 7, 13, -8 }, { 7, 13, -10 }, { 9, 14, -10 }, { 9, 14, -10 },
>  		{ 9, 15, -12 }, { 11, 15, -12 }, { 15, 16, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(10), 12,
>  	/* 10BPP/12BPC */
>  	{ 410, 15, 5632, 11, 20, 19, 19, {
>  		{ 0, 11, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 10, 14, -2 },
> @@ -461,7 +471,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 13, 18, -10 }, { 13, 19, -12 }, { 15, 19, -12 },
>  		{ 19, 20, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(10), 14,
>  	/* 10BPP/14BPC */
>  	{ 410, 15, 5632, 15, 24, 23, 23, {
>  		{ 0, 11, 2 }, { 5, 13, 0 }, { 11, 15, 0 }, { 13, 18, -2 },
> @@ -470,7 +482,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 17, 22, -10 }, { 17, 23, -12 }, { 19, 23, -12 },
>  		{ 23, 24, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(10), 16,
>  	/* 10BPP/16BPC */
>  	{ 410, 15, 5632, 19, 28, 27, 27, {
>  		{ 0, 11, 2 }, { 6, 14, 0 }, { 13, 17, 0 }, { 16, 20, -2 },
> @@ -479,9 +493,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 21, 26, -10 }, { 21, 27, -12 }, { 23, 27, -12 },
>  		{ 27, 28, -12 }
>  		}
> -	},
> +	}
>  },
> -{
> +{ DSC_BPP(12), 8,
>  	/* 12BPP/8BPC */
>  	{ 341, 15, 2048, 3, 12, 11, 11, {
>  		{ 0, 2, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> @@ -489,7 +503,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 },
>  		{ 5, 12, -12 }, { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(12), 10,
>  	/* 12BPP/10BPC */
>  	{ 341, 15, 2048, 7, 16, 15, 15, {
>  		{ 0, 2, 2 }, { 2, 5, 0 }, { 3, 7, 0 }, { 4, 8, -2 },
> @@ -497,7 +513,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
>  		{ 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(12), 12,
>  	/* 12BPP/12BPC */
>  	{ 341, 15, 2048, 11, 20, 19, 19, {
>  		{ 0, 6, 2 }, { 4, 9, 0 }, { 7, 11, 0 }, { 8, 12, -2 },
> @@ -506,7 +524,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
>  		{ 21, 23, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(12), 14,
>  	/* 12BPP/14BPC */
>  	{ 341, 15, 2048, 15, 24, 23, 23, {
>  		{ 0, 6, 2 }, { 7, 10, 0 }, { 9, 13, 0 }, { 11, 16, -2 },
> @@ -515,7 +535,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 17, 21, -12 }, { 17, 21, -12 }, { 19, 22, -12 },
>  		{ 22, 23, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(12), 16,
>  	/* 12BPP/16BPC */
>  	{ 341, 15, 2048, 19, 28, 27, 27, {
>  		{ 0, 6, 2 }, { 6, 11, 0 }, { 11, 15, 0 }, { 14, 18, -2 },
> @@ -524,9 +546,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 21, 25, -12 }, { 21, 25, -12 }, { 23, 26, -12 },
>  		{ 26, 27, -12 }
>  		}
> -	},
> +	}
>  },
> -{
> +{ DSC_BPP(15), 8,
>  	/* 15BPP/8BPC */
>  	{ 273, 15, 2048, 3, 12, 11, 11, {
>  		{ 0, 0, 10 }, { 0, 1, 8 }, { 0, 1, 6 }, { 0, 2, 4 },
> @@ -534,7 +556,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 2, 5, -6 }, { 3, 5, -8 }, { 4, 6, -10 }, { 4, 7, -10 },
>  		{ 5, 7, -12 }, { 7, 8, -12 }, { 8, 9, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(15), 10,
>  	/* 15BPP/10BPC */
>  	{ 273, 15, 2048, 7, 16, 15, 15, {
>  		{ 0, 2, 10 }, { 2, 5, 8 }, { 3, 5, 6 }, { 4, 6, 4 },
> @@ -542,7 +566,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 6, 9, -6 }, { 7, 9, -8 }, { 8, 10, -10 }, { 8, 11, -10 },
>  		{ 9, 11, -12 }, { 11, 12, -12 }, { 12, 13, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(15), 12,
>  	/* 15BPP/12BPC */
>  	{ 273, 15, 2048, 11, 20, 19, 19, {
>  		{ 0, 4, 10 }, { 2, 7, 8 }, { 4, 9, 6 }, { 6, 11, 4 },
> @@ -551,7 +577,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 13, 15, -10 }, { 13, 15, -12 }, { 15, 16, -12 },
>  		{ 16, 17, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(15), 14,
>  	/* 15BPP/14BPC */
>  	{ 273, 15, 2048, 15, 24, 23, 23, {
>  		{ 0, 4, 10 }, { 3, 8, 8 }, { 6, 11, 6 }, { 9, 14, 4 },
> @@ -560,7 +588,9 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 17, 19, -10 }, { 17, 19, -12 }, { 19, 20, -12 },
>  		{ 20, 21, -12 }
>  		}
> -	},
> +	}
> +},
> +{ DSC_BPP(15), 16,
>  	/* 15BPP/16BPC */
>  	{ 273, 15, 2048, 19, 28, 27, 27, {
>  		{ 0, 4, 10 }, { 4, 9, 8 }, { 8, 13, 6 }, { 12, 17, 4 },
> @@ -570,59 +600,21 @@ static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  		{ 24, 25, -12 }
>  		}
>  	}
> -}
> +},
> +{ /* sentinel */ }
>  };
>  
> -static int get_row_index_for_rc_params(u16 compressed_bpp)
> -{
> -	switch (compressed_bpp) {
> -	case 6:
> -		return ROW_INDEX_6BPP;
> -	case 8:
> -		return ROW_INDEX_8BPP;
> -	case 10:
> -		return ROW_INDEX_10BPP;
> -	case 12:
> -		return ROW_INDEX_12BPP;
> -	case 15:
> -		return ROW_INDEX_15BPP;
> -	default:
> -		return -EINVAL;
> -	}
> -}
> -
> -static int get_column_index_for_rc_params(u8 bits_per_component)
> -{
> -	switch (bits_per_component) {
> -	case 8:
> -		return COLUMN_INDEX_8BPC;
> -	case 10:
> -		return COLUMN_INDEX_10BPC;
> -	case 12:
> -		return COLUMN_INDEX_12BPC;
> -	case 14:
> -		return COLUMN_INDEX_14BPC;
> -	case 16:
> -		return COLUMN_INDEX_16BPC;
> -	default:
> -		return -EINVAL;
> -	}
> -}
> -
> -static const struct rc_parameters *get_rc_params(u16 compressed_bpp,
> +static const struct rc_parameters *get_rc_params(u16 dsc_bpp,
>  						 u8 bits_per_component)
>  {
> -	int row_index, column_index;
> -
> -	row_index = get_row_index_for_rc_params(compressed_bpp);
> -	if (row_index < 0)
> -		return NULL;
> +	int i;
>  
> -	column_index = get_column_index_for_rc_params(bits_per_component);
> -	if (column_index < 0)
> -		return NULL;
> +	for (i = 0; rc_parameters[i].bpp; i++)
> +		if (rc_parameters[i].bpp == dsc_bpp &&
> +		    rc_parameters[i].bpc == bits_per_component)
> +			return &rc_parameters[i].params;
>  
> -	return &rc_parameters[row_index][column_index];
> +	return NULL;
>  }
>  
>  /**
> @@ -636,11 +628,7 @@ int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg)
>  	const struct rc_parameters *rc_params;
>  	int i;
>  
> -	/* fractional BPP is not supported */
> -	if (vdsc_cfg->bits_per_pixel & 0xf)
> -		return -EINVAL;
> -
> -	rc_params = get_rc_params(vdsc_cfg->bits_per_pixel >> 4,
> +	rc_params = get_rc_params(vdsc_cfg->bits_per_pixel,
>  				  vdsc_cfg->bits_per_component);
>  	if (!rc_params)
>  		return -EINVAL;

-- 
Jani Nikula, Intel Open Source Graphics Center


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