Re: [PATCH 7/7] drm/i915/dp: Set the DSC link limits intel_dp_compute_config_link_bpp_limits

[Imre Deak <imre.deak@intel.com>]

On Thu, Oct 03, 2024 at 04:13:43PM +0530, Ankit Nautiyal wrote:
> The helper intel_dp_compute_config_link_bpp_limits is the correct place
> to set the DSC link limits. Move the code to this function and remove
> the #TODO item.
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 64 +++++++++++++------------
>  drivers/gpu/drm/i915/display/intel_dp.h |  4 +-
>  2 files changed, 35 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 02009ae03840..bfc31b3af864 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1958,7 +1958,7 @@ static int dsc_compute_link_config(struct intel_dp *intel_dp,
>  
>  static
>  u16 intel_dp_dsc_max_sink_compressed_bppx16(const struct intel_connector *connector,
> -					    struct intel_crtc_state *pipe_config,
> +					    const struct intel_crtc_state *pipe_config,
>  					    int bpc)
>  {
>  	u16 max_bppx16 = drm_edp_dsc_sink_output_bpp(connector->dp.dsc_dpcd);
> @@ -1983,7 +1983,7 @@ u16 intel_dp_dsc_max_sink_compressed_bppx16(const struct intel_connector *connec
>  	return 0;
>  }
>  
> -int intel_dp_dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config)
> +int intel_dp_dsc_sink_min_compressed_bpp(const struct intel_crtc_state *pipe_config)
>  {
>  	/* From Mandatory bit rate range Support Table 2-157 (DP v2.0) */
>  	switch (pipe_config->output_format) {
> @@ -2001,7 +2001,7 @@ int intel_dp_dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config)
>  }
>  
>  int intel_dp_dsc_sink_max_compressed_bpp(const struct intel_connector *connector,
> -					 struct intel_crtc_state *pipe_config,
> +					 const struct intel_crtc_state *pipe_config,
>  					 int bpc)
>  {
>  	return intel_dp_dsc_max_sink_compressed_bppx16(connector,
> @@ -2130,21 +2130,16 @@ static int dsc_compute_compressed_bpp(struct intel_dp *intel_dp,
>  {
>  	const struct drm_display_mode *adjusted_mode = &pipe_config->hw.adjusted_mode;
>  	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> -	int dsc_src_min_bpp, dsc_sink_min_bpp, dsc_min_bpp;
> -	int dsc_src_max_bpp, dsc_sink_max_bpp, dsc_max_bpp;
> +	int dsc_min_bpp;
> +	int dsc_max_bpp;
>  	int dsc_joiner_max_bpp;
>  	int num_joined_pipes = intel_crtc_num_joined_pipes(pipe_config);
>  
> -	dsc_src_min_bpp = dsc_src_min_compressed_bpp();
> -	dsc_sink_min_bpp = intel_dp_dsc_sink_min_compressed_bpp(pipe_config);
> -	dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp);
> -	dsc_min_bpp = max(dsc_min_bpp, fxp_q4_to_int_roundup(limits->link.min_bpp_x16));
> +	dsc_min_bpp = fxp_q4_to_int_roundup(limits->link.min_bpp_x16);
>  
> -	dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp);
> -	dsc_sink_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(connector,
> -								pipe_config,
> -								pipe_bpp / 3);
> -	dsc_max_bpp = dsc_sink_max_bpp ? min(dsc_sink_max_bpp, dsc_src_max_bpp) : dsc_src_max_bpp;
> +	dsc_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(connector,
> +							   pipe_config,
> +							   pipe_bpp / 3);
>  
>  	dsc_joiner_max_bpp = get_max_compressed_bpp_with_joiner(i915, adjusted_mode->clock,
>  								adjusted_mode->hdisplay,
> @@ -2255,8 +2250,8 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>  	struct intel_connector *connector =
>  		to_intel_connector(conn_state->connector);
>  	int pipe_bpp, forced_bpp;
> -	int dsc_src_min_bpp, dsc_sink_min_bpp, dsc_min_bpp;
> -	int dsc_src_max_bpp, dsc_sink_max_bpp, dsc_max_bpp;
> +	int dsc_min_bpp;
> +	int dsc_max_bpp;
>  
>  	forced_bpp = intel_dp_force_dsc_pipe_bpp(intel_dp, limits);
>  
> @@ -2276,16 +2271,12 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>  	pipe_config->port_clock = limits->max_rate;
>  	pipe_config->lane_count = limits->max_lane_count;
>  
> -	dsc_src_min_bpp = dsc_src_min_compressed_bpp();
> -	dsc_sink_min_bpp = intel_dp_dsc_sink_min_compressed_bpp(pipe_config);
> -	dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp);
> -	dsc_min_bpp = max(dsc_min_bpp, fxp_q4_to_int_roundup(limits->link.min_bpp_x16));
> +	dsc_min_bpp = fxp_q4_to_int_roundup(limits->link.min_bpp_x16);
> +
> +	dsc_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(connector,
> +							   pipe_config,
> +							   pipe_bpp / 3);
>  
> -	dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp);
> -	dsc_sink_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(connector,
> -								pipe_config,
> -								pipe_bpp / 3);
> -	dsc_max_bpp = dsc_sink_max_bpp ? min(dsc_sink_max_bpp, dsc_src_max_bpp) : dsc_src_max_bpp;
>  	dsc_max_bpp = min(dsc_max_bpp, fxp_q4_to_int(limits->link.max_bpp_x16));
>  
>  	/* Compressed BPP should be less than the Input DSC bpp */
> @@ -2428,6 +2419,7 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
>  		&crtc_state->hw.adjusted_mode;
>  	const struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	const struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> +	struct intel_connector *connector = intel_dp->attached_connector;

This would use the wrong (root) connector for MST.

>  	int max_link_bpp_x16;
>  
>  	max_link_bpp_x16 = min(crtc_state->max_link_bpp_x16,
> @@ -2441,12 +2433,22 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
>  
>  		limits->link.min_bpp_x16 = fxp_q4_from_int(limits->pipe.min_bpp);
>  	} else {
> -		/*
> -		 * TODO: set the DSC link limits already here, atm these are
> -		 * initialized only later in intel_edp_dsc_compute_pipe_bpp() /
> -		 * intel_dp_dsc_compute_pipe_bpp()
> -		 */
> -		limits->link.min_bpp_x16 = 0;
> +		int dsc_src_min_bpp, dsc_sink_min_bpp, dsc_min_bpp;
> +		int dsc_src_max_bpp, dsc_sink_max_bpp, dsc_max_bpp;
> +
> +		dsc_src_min_bpp = dsc_src_min_compressed_bpp();
> +		dsc_sink_min_bpp = intel_dp_dsc_sink_min_compressed_bpp(crtc_state);
> +		dsc_min_bpp = max(dsc_src_min_bpp, dsc_sink_min_bpp);
> +		limits->link.min_bpp_x16 = fxp_q4_from_int(dsc_min_bpp);
> +
> +		dsc_src_max_bpp = dsc_src_max_compressed_bpp(intel_dp);
> +		dsc_sink_max_bpp = intel_dp_dsc_sink_max_compressed_bpp(connector,
> +									crtc_state,
> +									limits->pipe.max_bpp / 3);
> +		dsc_max_bpp = dsc_sink_max_bpp ?
> +			      min(dsc_sink_max_bpp, dsc_src_max_bpp) : dsc_src_max_bpp;
> +
> +		max_link_bpp_x16 = min(max_link_bpp_x16, fxp_q4_from_int(dsc_max_bpp));
>  	}
>  
>  	limits->link.max_bpp_x16 = max_link_bpp_x16;
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
> index 8bd0bb4ec0e1..d4ca00ba49b4 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -145,9 +145,9 @@ u16 intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
>  					enum intel_output_format output_format,
>  					u32 pipe_bpp,
>  					u32 timeslots);
> -int intel_dp_dsc_sink_min_compressed_bpp(struct intel_crtc_state *pipe_config);
> +int intel_dp_dsc_sink_min_compressed_bpp(const struct intel_crtc_state *pipe_config);
>  int intel_dp_dsc_sink_max_compressed_bpp(const struct intel_connector *connector,
> -					 struct intel_crtc_state *pipe_config,
> +					 const struct intel_crtc_state *pipe_config,
>  					 int bpc);
>  u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
>  				int mode_clock, int mode_hdisplay,
> -- 
> 2.45.2
>