[PATCH 7/9] drm/i915/dp: Compute pixel replication count for DSC 12 slices case

[Kandpal, Suraj]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Ankit
> Nautiyal
> Sent: Monday, October 14, 2024 1:40 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org
> Subject: [PATCH 7/9] drm/i915/dp: Compute pixel replication count for DSC
> 12 slices case
> 
> Add check if pixel replication is required while computing slice count and fill
> the pixel replication count in crtc_state.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c     | 61 ++++++++++++++++++++-
>  drivers/gpu/drm/i915/display/intel_dp.h     |  2 +-
>  drivers/gpu/drm/i915/display/intel_dp_mst.c |  2 +
>  3 files changed, 63 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 6cfc7d1c96ea..ef96b9235636 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -981,13 +981,37 @@ u16
> intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>  	return bits_per_pixel;
>  }
> 
> +static
> +bool can_use_pixel_replication(int mode_hdisplay, u8 slice_count,
> +			       enum intel_output_format output_format,
> +			       bool ultrajoiner)
> +{

Shouldn't we also have a DISPLAY_VER check for safekeeping

Regards,
Suraj Kandpal
> +	int slice_width;
> +
> +	if (!(mode_hdisplay % slice_count))
> +		return false;
> +
> +	if (!ultrajoiner)
> +		return false;
> +
> +	slice_width = DIV_ROUND_UP(mode_hdisplay, slice_count);
> +
> +	/* Odd slice width is not supported by YCbCr420/422 formats */
> +	if (slice_width % 2 && output_format ==
> INTEL_OUTPUT_FORMAT_YCBCR420)
> +		return false;
> +
> +	return true;
> +}
> +
>  u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
>  				int mode_clock, int mode_hdisplay,
> +				enum intel_output_format output_format,
>  				int num_joined_pipes)
>  {
>  	struct drm_i915_private *i915 = to_i915(connector->base.dev);
>  	u8 min_slice_count, i;
>  	int max_slice_width;
> +	bool ultrajoiner = num_joined_pipes == 4 ? true : false;
> 
>  	if (mode_clock <= DP_DSC_PEAK_PIXEL_RATE)
>  		min_slice_count = DIV_ROUND_UP(mode_clock, @@ -1031,7
> +1055,10 @@ u8 intel_dp_dsc_get_slice_count(const struct intel_connector
> *connector,
>  		if (num_joined_pipes > 1 && valid_dsc_slicecount[i] < 2)
>  			continue;
> 
> -		if (mode_hdisplay % test_slice_count)
> +		if (mode_hdisplay % test_slice_count &&
> +		    !can_use_pixel_replication(mode_hdisplay,
> +					       test_slice_count,
> +					       output_format, ultrajoiner))
>  			continue;
> 
>  		if (min_slice_count <= test_slice_count) @@ -1458,6 +1485,7
> @@ intel_dp_mode_valid(struct drm_connector *_connector,
>  				intel_dp_dsc_get_slice_count(connector,
>  							     target_clock,
>  							     mode->hdisplay,
> +							     output_format,
> 
> num_joined_pipes);
>  		}
> 
> @@ -2322,6 +2350,33 @@ static int
> intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>  	return 0;
>  }
> 
> +static
> +int intel_dp_dsc_get_pixel_replication(struct intel_dp *intel_dp,
> +				       struct intel_crtc_state *pipe_config) {
> +	int mode_hdisplay = pipe_config->hw.adjusted_mode.hdisplay;
> +	int slice_count = pipe_config->dsc.slice_count;
> +	int pixel_replication_count;
> +	int slice_width;
> +	bool ultrajoiner = false;
> +
> +	if (intel_crtc_num_joined_pipes(pipe_config) == 4)
> +		ultrajoiner = true;
> +
> +	if (!can_use_pixel_replication(mode_hdisplay, slice_count,
> +				       pipe_config->output_format,
> ultrajoiner))
> +		return 0;
> +
> +	slice_width = DIV_ROUND_UP(mode_hdisplay, slice_count);
> +
> +	pixel_replication_count = (slice_width * slice_count) -
> mode_hdisplay;
> +
> +	if (pixel_replication_count >= 0)
> +		return pixel_replication_count;
> +
> +	return 0;
> +}
> +
>  int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
>  				struct intel_crtc_state *pipe_config,
>  				struct drm_connector_state *conn_state,
> @@ -2391,6 +2446,7 @@ int intel_dp_dsc_compute_config(struct intel_dp
> *intel_dp,
>  			intel_dp_dsc_get_slice_count(connector,
>  						     adjusted_mode-
> >crtc_clock,
>  						     adjusted_mode-
> >crtc_hdisplay,
> +						     pipe_config-
> >output_format,
>  						     num_joined_pipes);
>  		if (!dsc_dp_slice_count) {
>  			drm_dbg_kms(&dev_priv->drm,
> @@ -2400,6 +2456,9 @@ int intel_dp_dsc_compute_config(struct intel_dp
> *intel_dp,
> 
>  		pipe_config->dsc.slice_count = dsc_dp_slice_count;
>  	}
> +
> +	pipe_config->dsc.pixel_replication_count =
> +		intel_dp_dsc_get_pixel_replication(intel_dp, pipe_config);
>  	/*
>  	 * VDSC engine operates at 1 Pixel per clock, so if peak pixel rate
>  	 * is greater than the maximum Cdclock and if slice count is even diff
> --git a/drivers/gpu/drm/i915/display/intel_dp.h
> b/drivers/gpu/drm/i915/display/intel_dp.h
> index 60baf4072dc9..7ab86688a721 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -149,11 +149,11 @@ int
> intel_dp_dsc_sink_max_compressed_bpp(const struct intel_connector
> *connector
>  					 int bpc);
>  u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
>  				int mode_clock, int mode_hdisplay,
> +				enum intel_output_format output_format,
>  				int num_joined_pipes);
>  int intel_dp_num_joined_pipes(struct intel_dp *intel_dp,
>  			      struct intel_connector *connector,
>  			      int hdisplay, int clock);
> -
>  static inline unsigned int intel_dp_unused_lane_mask(int lane_count)  {
>  	return ~((1 << lane_count) - 1) & 0xf; diff --git
> a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 4765bda154c1..4cb44d88a642 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -109,6 +109,7 @@ static int intel_dp_mst_bw_overhead(const struct
> intel_crtc_state *crtc_state,
>  		dsc_slice_count = intel_dp_dsc_get_slice_count(connector,
>  							       adjusted_mode-
> >clock,
>  							       adjusted_mode-
> >hdisplay,
> +							       crtc_state-
> >output_format,
> 
> num_joined_pipes);
>  	}
> 
> @@ -1506,6 +1507,7 @@ intel_dp_mst_mode_valid_ctx(struct
> drm_connector *connector,
> 
> 	intel_dp_dsc_get_slice_count(intel_connector,
>  							     target_clock,
>  							     mode->hdisplay,
> +
> INTEL_OUTPUT_FORMAT_RGB,
> 
> num_joined_pipes);
>  		}
> 
> --
> 2.45.2