[PATCH 08/14] drm/i915/dp: Unify DSC link config functions

[Imre Deak]

On Fri, Jan 31, 2025 at 02:50:01PM +0200, Jani Nikula wrote:
> {icl,xelpd}_dsc_compute_link_config() are now effectively the same, and
> can be unified to a single platform independent function.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Reviewed-by: Imre Deak <imre.deak at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 49 +++----------------------
>  1 file changed, 5 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index c7de9efcd740..11a1ac28e21e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2094,47 +2094,11 @@ static bool intel_dp_dsc_valid_bpp(struct intel_dp *intel_dp, int bpp_x16)
>  }
>  
>  /*
> - * From a list of valid compressed bpps try different compressed bpp and find a
> - * suitable link configuration that can support it.
> + * Find the max compressed BPP we can find a link configuration for. The BPPs to
> + * try depend on the source (platform) and sink.
>   */
>  static int
> -icl_dsc_compute_link_config(struct intel_dp *intel_dp,
> -			    struct intel_crtc_state *pipe_config,
> -			    const struct link_config_limits *limits,
> -			    int min_bpp_x16,
> -			    int max_bpp_x16,
> -			    int bpp_step_x16,
> -			    int timeslots)
> -{
> -	int bpp_x16;
> -	int ret;
> -
> -	for (bpp_x16 = max_bpp_x16; bpp_x16 >= min_bpp_x16; bpp_x16 -= bpp_step_x16) {
> -		if (!intel_dp_dsc_valid_bpp(intel_dp, bpp_x16))
> -			continue;
> -
> -		ret = dsc_compute_link_config(intel_dp,
> -					      pipe_config,
> -					      limits,
> -					      bpp_x16,
> -					      timeslots);
> -		if (ret == 0) {
> -			pipe_config->dsc.compressed_bpp_x16 = bpp_x16;
> -			return 0;
> -		}
> -	}
> -
> -	return -EINVAL;
> -}
> -
> -/*
> - * From XE_LPD onwards we supports compression bpps in steps of 1 up to
> - * uncompressed bpp-1. So we start from max compressed bpp and see if any
> - * link configuration is able to support that compressed bpp, if not we
> - * step down and check for lower compressed bpp.
> - */
> -static int
> -xelpd_dsc_compute_link_config(struct intel_dp *intel_dp,
> +do_dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
>  			      struct intel_crtc_state *pipe_config,
>  			      const struct link_config_limits *limits,
>  			      int min_bpp_x16,
> @@ -2201,11 +2165,8 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
>  	output_bpp = intel_dp_output_bpp(pipe_config->output_format, pipe_bpp);
>  	max_bpp_x16 = min(max_bpp_x16, fxp_q4_from_int(output_bpp) - bpp_step_x16);
>  
> -	if (DISPLAY_VER(display) >= 13)
> -		return xelpd_dsc_compute_link_config(intel_dp, pipe_config, limits,
> -						     min_bpp_x16, max_bpp_x16, bpp_step_x16, timeslots);
> -	return icl_dsc_compute_link_config(intel_dp, pipe_config, limits,
> -					   min_bpp_x16, max_bpp_x16, bpp_step_x16, timeslots);
> +	return do_dsc_compute_compressed_bpp(intel_dp, pipe_config, limits,
> +					     min_bpp_x16, max_bpp_x16, bpp_step_x16, timeslots);
>  }
>  
>  int intel_dp_dsc_min_src_input_bpc(void)
> -- 
> 2.39.5
>