Re: [Intel-gfx] [PATCH 16/20] drm/i915/dp: Separate out function to get compressed bpp with joiner

["Lisovskiy, Stanislav" <stanislav.lisovskiy@intel.com>]

On Fri, Jul 28, 2023 at 09:41:46AM +0530, Ankit Nautiyal wrote:
> Pull the code to get joiner constraints on maximum compressed bpp into
> separate function.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 54 ++++++++++++++-----------
>  1 file changed, 30 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index b296db026fd8..9720d32c6301 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -740,6 +740,32 @@ u32 intel_dp_dsc_nearest_valid_bpp(struct drm_i915_private *i915, u32 bpp, u32 p
>  	return bits_per_pixel;
>  }

Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>

>  
> +static
> +u32 get_max_compressed_bpp_with_joiner(struct drm_i915_private *i915,
> +				       u32 mode_clock, u32 mode_hdisplay,
> +				       bool bigjoiner)
> +{
> +	u32 max_bpp_small_joiner_ram;
> +
> +	/* Small Joiner Check: output bpp <= joiner RAM (bits) / Horiz. width */
> +	max_bpp_small_joiner_ram = small_joiner_ram_size_bits(i915) / mode_hdisplay;
> +
> +	if (bigjoiner) {
> +		int bigjoiner_interface_bits = DISPLAY_VER(i915) >= 14 ? 36 : 24;
> +		/* With bigjoiner multiple dsc engines are used in parallel so PPC is 2 */
> +		int ppc = 2;
> +		u32 max_bpp_bigjoiner =
> +			i915->display.cdclk.max_cdclk_freq * ppc * bigjoiner_interface_bits /
> +			intel_dp_mode_to_fec_clock(mode_clock);
> +
> +		max_bpp_small_joiner_ram *= 2;
> +
> +		return min(max_bpp_small_joiner_ram, max_bpp_bigjoiner);
> +	}
> +
> +	return max_bpp_small_joiner_ram;
> +}
> +
>  u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>  					u32 link_clock, u32 lane_count,
>  					u32 mode_clock, u32 mode_hdisplay,
> @@ -748,7 +774,7 @@ u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>  					u32 pipe_bpp,
>  					u32 timeslots)
>  {
> -	u32 bits_per_pixel, max_bpp_small_joiner_ram;
> +	u32 bits_per_pixel, joiner_max_bpp;
>  
>  	/*
>  	 * Available Link Bandwidth(Kbits/sec) = (NumberOfLanes)*
> @@ -788,29 +814,9 @@ u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>  				(link_clock * lane_count * 8),
>  				intel_dp_mode_to_fec_clock(mode_clock));
>  
> -	/* Small Joiner Check: output bpp <= joiner RAM (bits) / Horiz. width */
> -	max_bpp_small_joiner_ram = small_joiner_ram_size_bits(i915) /
> -		mode_hdisplay;
> -
> -	if (bigjoiner)
> -		max_bpp_small_joiner_ram *= 2;
> -
> -	/*
> -	 * Greatest allowed DSC BPP = MIN (output BPP from available Link BW
> -	 * check, output bpp from small joiner RAM check)
> -	 */
> -	bits_per_pixel = min(bits_per_pixel, max_bpp_small_joiner_ram);
> -
> -	if (bigjoiner) {
> -		int bigjoiner_interface_bits = DISPLAY_VER(i915) >= 14 ? 36 : 24;
> -		/* With bigjoiner multiple dsc engines are used in parallel so PPC is 2 */
> -		int ppc = 2;
> -		u32 max_bpp_bigjoiner =
> -			i915->display.cdclk.max_cdclk_freq * ppc * bigjoiner_interface_bits /
> -			intel_dp_mode_to_fec_clock(mode_clock);
> -
> -		bits_per_pixel = min(bits_per_pixel, max_bpp_bigjoiner);
> -	}
> +	joiner_max_bpp = get_max_compressed_bpp_with_joiner(i915, mode_clock,
> +							    mode_hdisplay, bigjoiner);
> +	bits_per_pixel = min(bits_per_pixel, joiner_max_bpp);
>  
>  	bits_per_pixel = intel_dp_dsc_nearest_valid_bpp(i915, bits_per_pixel, pipe_bpp);
>  
> -- 
> 2.40.1
>