Re: [PATCH 10/14] drm/i915/display/vdsc: Add ultrajoiner support with DSC

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Sep 06, 2024 at 06:28:03PM +0530, Ankit Nautiyal wrote:
> From: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> 
> Add changes to DSC which are required for Ultrajoiner.
> 
> v2:
> -Use correct helper for setting bits for bigjoiner secondary. (Ankit)
> -Use enum for joiner pipe count instead magic numbers. (Suraj)
> -Use primary/secondary instead of master/slave. (Suraj)
> 
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_vdsc.c | 26 +++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
> index 8158e3702ed5..66e810c8de68 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> @@ -379,9 +379,11 @@ static int intel_dsc_get_vdsc_per_pipe(const struct intel_crtc_state *crtc_state
>  int intel_dsc_get_num_vdsc_instances(const struct intel_crtc_state *crtc_state)
>  {
>  	int num_vdsc_instances = intel_dsc_get_vdsc_per_pipe(crtc_state);
> +	int joined_pipes = intel_joiner_num_pipes(crtc_state);
>  
> -	if (crtc_state->joiner_pipes)
> -		num_vdsc_instances *= 2;
> +	if (joined_pipes == INTEL_BIG_JOINER_PIPES ||
> +	    joined_pipes == INTEL_ULTRA_JOINER_PIPES)
> +		num_vdsc_instances *= joined_pipes;
>  
>  	return num_vdsc_instances;
>  }
> @@ -751,6 +753,14 @@ void intel_uncompressed_joiner_enable(const struct intel_crtc_state *crtc_state)
>  	}
>  }
>  
> +static bool intel_crtc_ultrajoiner_enable_needed(const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> +
> +	return intel_joiner_num_pipes(crtc_state) == INTEL_ULTRA_JOINER_PIPES &&
> +	       crtc->pipe != PIPE_D;
> +}
> +
>  void intel_dsc_enable(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> @@ -770,7 +780,19 @@ void intel_dsc_enable(const struct intel_crtc_state *crtc_state)
>  		dss_ctl1_val |= JOINER_ENABLE;
>  	}
>  	if (crtc_state->joiner_pipes) {
> +		/*
> +		 * This bit doesn't seem to follow primary/secondary logic or
> +		 * any other logic, so lets just add helper function to
> +		 * at least hide this hassle..
> +		 */
> +		if (intel_crtc_ultrajoiner_enable_needed(crtc_state))

What is this crazyness? This would throw a big wrench into
the works, eg. the ultrajoiner readout would not work as intended.

> +			dss_ctl1_val |= ULTRA_JOINER_ENABLE;
> +
> +		if (intel_crtc_is_ultrajoiner_primary(crtc_state))
> +			dss_ctl1_val |= PRIMARY_ULTRA_JOINER_ENABLE;
> +
>  		dss_ctl1_val |= BIG_JOINER_ENABLE;
> +
>  		if (intel_crtc_is_bigjoiner_primary(crtc_state))
>  			dss_ctl1_val |= PRIMARY_BIG_JOINER_ENABLE;
>  	}
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel