Re: [PATCH 4/6] drm/i915/display: Compute AS SDP parameters.

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 2/22/2024 5:42 PM, Mitul Golani wrote:
> Add necessary functions definitions to enable
> and compute AS SDP data. The new `intel_dp_compute_as_sdp`
> function computes AS SDP values based on the display
> configuration, ensuring proper handling of Variable Refresh
> Rate (VRR).
>
> --v2:
> - Add DP_SDP_ADAPTIVE_SYNC to infoframe_type_to_idx().[Ankit]
> - separate patch for intel_read/write_dp_sdp [Ankit].
> - _HSW_VIDEO_DIP_ASYNC_DATA_A should be from ADL onward [Ankit]
> - To fix indentation [Ankit]
>
> --v3:
> - Add VIDEO_DIP_ENABLE_AS_HSW flag to intel_dp_set_infoframes.
>
> --v4:
> - Add HAS_VRR check before write as sdp.
>
> --v5:
> - Add missed HAS_VRR check before read as sdp.
>
> --v6:
> Use Adaptive Sync sink status, which can be
> used as a check for read/write sdp. (Ankit)
>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
> ---
>   .../drm/i915/display/intel_display_types.h    |  1 +
>   drivers/gpu/drm/i915/display/intel_dp.c       | 28 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_vrr.c      |  4 ++-
>   3 files changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 2accfe41160d..93b4b7dff1d0 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1415,6 +1415,7 @@ struct intel_crtc_state {
>   		u8 pipeline_full;
>   		u16 flipline, vmin, vmax, guardband;
>   		u8 as_sdp_mode;
> +		bool as_sdp_enable;

This is again specific to DP, we can do away with this in vrr struct.

>   	} vrr;
>   
>   	/* Stream Splitter for eDP MSO */
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index b370e1da4735..5c1e2301dd52 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2617,6 +2617,33 @@ static void intel_dp_compute_vsc_colorimetry(const struct intel_crtc_state *crtc
>   	vsc->content_type = DP_CONTENT_TYPE_NOT_DEFINED;
>   }
>   
> +static void intel_dp_compute_as_sdp(struct intel_dp *intel_dp,
> +				    struct intel_crtc_state *crtc_state,
> +				    const struct drm_connector_state *conn_state)
> +{
> +	struct drm_dp_as_sdp *as_sdp = &crtc_state->infoframes.as_sdp;
> +	struct intel_connector *connector = intel_dp->attached_connector;
> +	const struct drm_display_mode *adjusted_mode =
> +		&crtc_state->hw.adjusted_mode;
> +	int vrefresh = drm_mode_vrefresh(adjusted_mode);
> +
> +	if (!intel_vrr_is_in_range(connector, vrefresh) || !crtc_state->vrr.as_sdp_enable)
> +		return;
> +
> +	as_sdp->sdp_type = DP_SDP_ADAPTIVE_SYNC;
> +	as_sdp->length = 0x9;
> +	as_sdp->mode = crtc_state->vrr.as_sdp_mode;
> +	as_sdp->vtotal = adjusted_mode->vtotal;
> +
> +	if (as_sdp->mode == DP_AS_SDP_AVT_FIXED_VTOTAL) {

Currently we are just supporting DP_AS_SDP_AVT_FIXED_VTOTAL so this 
check is not required.

But we can add a comment mentioning the same.


> +		as_sdp->target_rr = 0;
> +		as_sdp->duration_incr_ms = 0;
> +		as_sdp->duration_incr_ms = 0;
> +	}
> +
> +	crtc_state->infoframes.enable |= intel_hdmi_infoframe_enable(DP_SDP_ADAPTIVE_SYNC);
> +}

We will need to add this to state checker, something like 
PIPE_CONF_CHECK_DP_AS_SDP and add function to compare the adaptive sync 
sdp struct.


Regards,

Ankit

> +
>   static void intel_dp_compute_vsc_sdp(struct intel_dp *intel_dp,
>   				     struct intel_crtc_state *crtc_state,
>   				     const struct drm_connector_state *conn_state)
> @@ -2942,6 +2969,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>   		g4x_dp_set_clock(encoder, pipe_config);
>   
>   	intel_vrr_compute_config(pipe_config, conn_state);
> +	intel_dp_compute_as_sdp(intel_dp, pipe_config, conn_state);
>   	intel_psr_compute_config(intel_dp, pipe_config, conn_state);
>   	intel_dp_drrs_compute_config(connector, pipe_config, link_bpp_x16);
>   	intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index d2ab7e571e62..08e3ba69bd30 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -167,9 +167,11 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>   		crtc_state->vrr.enable = true;
>   		crtc_state->mode_flags |= I915_MODE_FLAG_VRR;
>   
> -		if (drm_dp_as_sdp_supported(&intel_dp->aux, intel_dp->dpcd))
> +		if (drm_dp_as_sdp_supported(&intel_dp->aux, intel_dp->dpcd)) {
> +			crtc_state->vrr.as_sdp_enable = true;
>   			crtc_state->vrr.as_sdp_mode =
>   						DP_AS_SDP_AVT_DYNAMIC_VTOTAL;
> +		}
>   	}
>   }
>