Re: [PATCH 11/14] drm/i915/dp_mst: Refactor pipe_bpp limits with dsc for mst

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 04 Dec 2024, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
> Similar to DP, set the dsc limits->pipe.max/min_bpp early for MST too.
> Use the limits while computing the compressed bpp.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>

I think we should take this one step further with [1], basically
eradicating mst_stream_compute_config_limits(). Indeed, I'd like to get
that merged first.

BR,
Jani.



[1] https://lore.kernel.org/r/20241211144310.701895-1-jani.nikula@intel.com



> ---
>  drivers/gpu/drm/i915/display/intel_dp.c     |  2 +-
>  drivers/gpu/drm/i915/display/intel_dp.h     |  3 +++
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 11 +++++------
>  3 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index fe0957e028bc..c5740b8d2315 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2504,7 +2504,7 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
>  	return true;
>  }
>  
> -static void
> +void
>  intel_dp_dsc_compute_pipe_bpp_limits(struct intel_dp *intel_dp,
>  				     struct link_config_limits *limits)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
> index 4895b52d41e8..45b37d322565 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -200,6 +200,9 @@ intel_dp_compute_config_link_bpp_limits(struct intel_dp *intel_dp,
>  					const struct intel_crtc_state *crtc_state,
>  					bool dsc,
>  					struct link_config_limits *limits);
> +void
> +intel_dp_dsc_compute_pipe_bpp_limits(struct intel_dp *intel_dp,
> +				     struct link_config_limits *limits);
>  
>  void intel_dp_get_dsc_sink_cap(u8 dpcd_rev, struct intel_connector *connector);
>  bool intel_dp_has_gamut_metadata_dip(struct intel_encoder *encoder);
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 795594191717..667006918bfd 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -365,14 +365,10 @@ static int mst_stream_dsc_compute_link_config(struct intel_dp *intel_dp,
>  	int i, num_bpc;
>  	u8 dsc_bpc[3] = {};
>  	int min_bpp, max_bpp, sink_min_bpp, sink_max_bpp;
> -	int dsc_max_bpc, dsc_min_bpc;
>  	int min_compressed_bpp, max_compressed_bpp;
>  
> -	dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(display);
> -	dsc_min_bpc = intel_dp_dsc_min_src_input_bpc();
> -
> -	max_bpp = min(dsc_max_bpc * 3, limits->pipe.max_bpp);
> -	min_bpp = max(dsc_min_bpc * 3, limits->pipe.min_bpp);
> +	max_bpp = limits->pipe.max_bpp;
> +	min_bpp = limits->pipe.min_bpp;
>  
>  	num_bpc = drm_dp_dsc_sink_supported_input_bpcs(connector->dp.dsc_dpcd,
>  						       dsc_bpc);
> @@ -574,6 +570,9 @@ mst_stream_compute_config_limits(struct intel_dp *intel_dp,
>  
>  	intel_dp_test_compute_config(intel_dp, crtc_state, limits);
>  
> +	if (dsc)
> +		intel_dp_dsc_compute_pipe_bpp_limits(intel_dp, limits);
> +
>  	if (!intel_dp_compute_config_link_bpp_limits(intel_dp,
>  						     crtc_state,
>  						     dsc,

-- 
Jani Nikula, Intel