[Intel-gfx] [PATCH v2 2/4] drm/i915/dsc: clean up rc parameter table access

[Manasi Navare]

On Mon, Nov 04, 2019 at 04:14:37PM +0200, Jani Nikula wrote:
> Use a simple pointer to the relevant element instead of duplicating the
> array subscription. No functional changes.
> 
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Thank you for the cleanup and optimizations in this patch,

Reviewed-by: Manasi Navare <manasi.d.navare at intel.com>

Manasi

> ---
>  drivers/gpu/drm/i915/display/intel_vdsc.c | 55 ++++++++++++-----------
>  1 file changed, 30 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
> index 763f1d7208e9..f1df654369a7 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> @@ -53,7 +53,7 @@ struct rc_parameters {
>   * Selected Rate Control Related Parameter Recommended Values
>   * from DSC_v1.11 spec & C Model release: DSC_model_20161212
>   */
> -static const struct rc_parameters rc_params[][MAX_COLUMN_INDEX] = {
> +static const struct rc_parameters rc_parameters[][MAX_COLUMN_INDEX] = {
>  {
>  	/* 6BPP/8BPC */
>  	{ 768, 15, 6144, 3, 13, 11, 11, {
> @@ -319,14 +319,29 @@ static int get_column_index_for_rc_params(u8 bits_per_component)
>  	}
>  }
>  
> +static const struct rc_parameters *get_rc_params(u16 compressed_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;
> +
> +	column_index = get_column_index_for_rc_params(bits_per_component);
> +	if (column_index < 0)
> +		return NULL;
> +
> +	return &rc_parameters[row_index][column_index];
> +}
> +
>  int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
>  				struct intel_crtc_state *pipe_config)
>  {
>  	struct drm_dsc_config *vdsc_cfg = &pipe_config->dsc.config;
>  	u16 compressed_bpp = pipe_config->dsc.compressed_bpp;
> +	const struct rc_parameters *rc_params;
>  	u8 i = 0;
> -	int row_index = 0;
> -	int column_index = 0;
>  	u8 line_buf_depth = 0;
>  
>  	vdsc_cfg->pic_width = pipe_config->hw.adjusted_mode.crtc_hdisplay;
> @@ -399,39 +414,29 @@ int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
>  		vdsc_cfg->rc_buf_thresh[13] = 0x7D;
>  	}
>  
> -	row_index = get_row_index_for_rc_params(compressed_bpp);
> -	column_index =
> -		get_column_index_for_rc_params(vdsc_cfg->bits_per_component);
> -
> -	if (row_index < 0 || column_index < 0)
> +	rc_params = get_rc_params(compressed_bpp, vdsc_cfg->bits_per_component);
> +	if (!rc_params)
>  		return -EINVAL;
>  
> -	vdsc_cfg->first_line_bpg_offset =
> -		rc_params[row_index][column_index].first_line_bpg_offset;
> -	vdsc_cfg->initial_xmit_delay =
> -		rc_params[row_index][column_index].initial_xmit_delay;
> -	vdsc_cfg->initial_offset =
> -		rc_params[row_index][column_index].initial_offset;
> -	vdsc_cfg->flatness_min_qp =
> -		rc_params[row_index][column_index].flatness_min_qp;
> -	vdsc_cfg->flatness_max_qp =
> -		rc_params[row_index][column_index].flatness_max_qp;
> -	vdsc_cfg->rc_quant_incr_limit0 =
> -		rc_params[row_index][column_index].rc_quant_incr_limit0;
> -	vdsc_cfg->rc_quant_incr_limit1 =
> -		rc_params[row_index][column_index].rc_quant_incr_limit1;
> +	vdsc_cfg->first_line_bpg_offset = rc_params->first_line_bpg_offset;
> +	vdsc_cfg->initial_xmit_delay = rc_params->initial_xmit_delay;
> +	vdsc_cfg->initial_offset = rc_params->initial_offset;
> +	vdsc_cfg->flatness_min_qp = rc_params->flatness_min_qp;
> +	vdsc_cfg->flatness_max_qp = rc_params->flatness_max_qp;
> +	vdsc_cfg->rc_quant_incr_limit0 = rc_params->rc_quant_incr_limit0;
> +	vdsc_cfg->rc_quant_incr_limit1 = rc_params->rc_quant_incr_limit1;
>  
>  	for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
>  		vdsc_cfg->rc_range_params[i].range_min_qp =
> -			rc_params[row_index][column_index].rc_range_params[i].range_min_qp;
> +			rc_params->rc_range_params[i].range_min_qp;
>  		vdsc_cfg->rc_range_params[i].range_max_qp =
> -			rc_params[row_index][column_index].rc_range_params[i].range_max_qp;
> +			rc_params->rc_range_params[i].range_max_qp;
>  		/*
>  		 * Range BPG Offset uses 2's complement and is only a 6 bits. So
>  		 * mask it to get only 6 bits.
>  		 */
>  		vdsc_cfg->rc_range_params[i].range_bpg_offset =
> -			rc_params[row_index][column_index].rc_range_params[i].range_bpg_offset &
> +			rc_params->rc_range_params[i].range_bpg_offset &
>  			DSC_RANGE_BPG_OFFSET_MASK;
>  	}
>  
> -- 
> 2.20.1
>