Commit 52ecd48b authored by Ankit Nautiyal's avatar Ankit Nautiyal
Browse files

drm/i915/dp: Add helper to get min sdp guardband 



Add a helper to compute vblank time needed for transmitting specific
DisplayPort SDPs like PPS, GAMUT_METADATA, and VSC_EXT. Latency is
based on line count per packet type.

This will be used to ensure adequate guardband when features like DSC/HDR
are enabled.

v2: Correct the lines required for PPS SDP. (Jouni)

Bspec: 70151
Signed-off-by: default avatarAnkit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: default avatarJouni Högander <jouni.hogander@intel.com>
Link: https://lore.kernel.org/r/20251017123504.2247954-3-ankit.k.nautiyal@intel.com
parent 77fb33cb

drivers/gpu/drm/i915/display/intel_dp.c

+36 −0
Original line number Diff line number Diff line
@@ -7002,3 +7002,39 @@ int intel_dp_compute_config_late(struct intel_encoder *encoder, 


	return 0;

}



static

int intel_dp_get_lines_for_sdp(u32 type)

{

	switch (type) {

	case DP_SDP_VSC_EXT_VESA:

	case DP_SDP_VSC_EXT_CEA:

		return 10;

	case HDMI_PACKET_TYPE_GAMUT_METADATA:

		return 8;

	case DP_SDP_PPS:

		return 7;

	default:

		break;

	}



	return 0;

}



int intel_dp_sdp_min_guardband(const struct intel_crtc_state *crtc_state,

			       bool assume_all_enabled)

{

	int sdp_guardband = 0;



	if (assume_all_enabled ||

	    crtc_state->infoframes.enable &

	    intel_hdmi_infoframe_enable(HDMI_PACKET_TYPE_GAMUT_METADATA))

		sdp_guardband = max(sdp_guardband,

				    intel_dp_get_lines_for_sdp(HDMI_PACKET_TYPE_GAMUT_METADATA));



	if (assume_all_enabled ||

	    crtc_state->dsc.compression_enable)

		sdp_guardband = max(sdp_guardband, intel_dp_get_lines_for_sdp(DP_SDP_PPS));



	return sdp_guardband;

}

drivers/gpu/drm/i915/display/intel_dp.h

+2 −0
Original line number Diff line number Diff line
@@ -223,5 +223,7 @@ bool intel_dp_in_hdr_mode(const struct drm_connector_state *conn_state); 
int intel_dp_compute_config_late(struct intel_encoder *encoder,

				 struct intel_crtc_state *crtc_state,

				 struct drm_connector_state *conn_state);

int intel_dp_sdp_min_guardband(const struct intel_crtc_state *crtc_state,

			       bool assume_all_enabled);



#endif /* __INTEL_DP_H__ */