[PATCH 01/14] drm/i915/dp: Refactor FEC support check in intel_dp_supports_dsc

[Kandpal, Suraj]

> -----Original Message-----
> From: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>
> Sent: Wednesday, December 4, 2024 2:56 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org; Kandpal, Suraj <suraj.kandpal at intel.com>;
> jani.nikula at linux.intel.com; Deak, Imre <imre.deak at intel.com>
> Subject: [PATCH 01/14] drm/i915/dp: Refactor FEC support check in
> intel_dp_supports_dsc
> 
> Forward Error Correction is required for DP if we are using DSC but is optional
> for eDP.
> 
> Currently the helper intel_dp_supports_dsc checks if fec_enable is set for DP
> or not. The helper is called after fec_enable is set in crtc_state.
> 
> Instead of this a better approach would be to:
> first, call intel_dp_supports_dsc to check for DSC support (along with FEC
> requirement for DP) and then set fec_enable for DP (if not already set) in
> crtc_state.
> 
> To achieve this, remove the check for fec_enable in the helper and instead
> check for FEC support for DP. With this change the helper
> intel_dp_supports_dsc can be called earlier and return early if DSC is not
> supported. The structure intel_dp is added to the helper to get the FEC
> support for DP.
> 
> v2: Pass intel_dp to adjust_limits_for_dsc_hblank_expansion_quirk
> instead of deriving it from connector. (Jani)
> 

LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>

> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp.c     |  8 +++++---
>  drivers/gpu/drm/i915/display/intel_dp.h     |  3 ++-
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 10 ++++++----
>  3 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4471c8fcd478..eb65c7a64a32 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1624,13 +1624,15 @@ bool intel_dp_supports_fec(struct intel_dp
> *intel_dp,
>  		drm_dp_sink_supports_fec(connector->dp.fec_capability);
>  }
> 
> -bool intel_dp_supports_dsc(const struct intel_connector *connector,
> +bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
> +			   const struct intel_connector *connector,
>  			   const struct intel_crtc_state *crtc_state)  {
>  	if (!intel_dp_has_dsc(connector))
>  		return false;
> 
> -	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && !crtc_state-
> >fec_enable)
> +	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) &&
> +	    !intel_dp_supports_fec(intel_dp, connector, crtc_state))
>  		return false;
> 
>  	return intel_dsc_source_support(crtc_state);
> @@ -2368,7 +2370,7 @@ int intel_dp_dsc_compute_config(struct intel_dp
> *intel_dp,
>  		 intel_dp_supports_fec(intel_dp, connector, pipe_config) &&
>  		 !intel_dp_is_uhbr(pipe_config));
> 
> -	if (!intel_dp_supports_dsc(connector, pipe_config))
> +	if (!intel_dp_supports_dsc(intel_dp, connector, pipe_config))
>  		return -EINVAL;
> 
>  	if (!intel_dp_dsc_supports_format(connector, pipe_config-
> >output_format)) diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
> b/drivers/gpu/drm/i915/display/intel_dp.h
> index 48f10876be65..4ae54e9718ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -170,7 +170,8 @@ bool intel_dp_supports_fec(struct intel_dp *intel_dp,
>  			   const struct intel_connector *connector,
>  			   const struct intel_crtc_state *pipe_config);
> 
> -bool intel_dp_supports_dsc(const struct intel_connector *connector,
> +bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
> +			   const struct intel_connector *connector,
>  			   const struct intel_crtc_state *crtc_state);
> 
>  u32 intel_dp_dsc_nearest_valid_bpp(struct drm_i915_private *i915, u32
> bpp, u32 pipe_bpp); diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index c59c2c14679c..9b64c8a0e55e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -488,7 +488,8 @@ hblank_expansion_quirk_needs_dsc(const struct
> intel_connector *connector,  }
> 
>  static bool
> -adjust_limits_for_dsc_hblank_expansion_quirk(const struct intel_connector
> *connector,
> +adjust_limits_for_dsc_hblank_expansion_quirk(struct intel_dp *intel_dp,
> +					     const struct intel_connector
> *connector,
>  					     const struct intel_crtc_state
> *crtc_state,
>  					     struct link_config_limits *limits,
>  					     bool dsc)
> @@ -501,7 +502,7 @@ adjust_limits_for_dsc_hblank_expansion_quirk(const
> struct intel_connector *conne
>  		return true;
> 
>  	if (!dsc) {
> -		if (intel_dp_supports_dsc(connector, crtc_state)) {
> +		if (intel_dp_supports_dsc(intel_dp, connector, crtc_state)) {
>  			drm_dbg_kms(display->drm,
>  				    "[CRTC:%d:%s][CONNECTOR:%d:%s] DSC
> needed by hblank expansion quirk\n",
>  				    crtc->base.base.id, crtc->base.name, @@ -
> 582,7 +583,8 @@ mst_stream_compute_config_limits(struct intel_dp
> *intel_dp,
>  						     limits))
>  		return false;
> 
> -	return adjust_limits_for_dsc_hblank_expansion_quirk(connector,
> +	return adjust_limits_for_dsc_hblank_expansion_quirk(intel_dp,
> +							    connector,
>  							    crtc_state,
>  							    limits,
>  							    dsc);
> @@ -646,7 +648,7 @@ static int mst_stream_compute_config(struct
> intel_encoder *encoder,
>  			    str_yes_no(ret), str_yes_no(joiner_needs_dsc),
>  			    str_yes_no(intel_dp->force_dsc_en));
> 
> -		if (!intel_dp_supports_dsc(connector, pipe_config))
> +		if (!intel_dp_supports_dsc(intel_dp, connector, pipe_config))
>  			return -EINVAL;
> 
>  		if (!mst_stream_compute_config_limits(intel_dp, connector,
> --
> 2.45.2