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 and current line time.
Used to ensure adequate vblank when features like DSC/HDR are enabled.
Bspec: 70151
Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
Reviewed-by: Mitul Golani <mitulkumar.ajitkumar.gol...@intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 47 +++++++++++++++++++++++++
drivers/gpu/drm/i915/display/intel_dp.h | 1 +
2 files changed, 48 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
b/drivers/gpu/drm/i915/display/intel_dp.c
index 996edb8deded..4dc1ce383b8e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -6842,3 +6842,50 @@ void intel_dp_mst_resume(struct intel_display *display)
}
}
}
+
+static
+int intel_dp_get_sdp_latency(u32 type, int linetime_us)
+{
+ int lines;
+
+ switch (type) {
+ case DP_SDP_VSC_EXT_VESA:
+ case DP_SDP_VSC_EXT_CEA:
+ lines = 10;
+ break;
+ case HDMI_PACKET_TYPE_GAMUT_METADATA:
+ lines = 8;
+ break;
+ case DP_SDP_PPS:
+ lines = 6;
+ break;
+ default:
+ lines = 0;
+ break;
+ }
+
+ return lines * linetime_us;
+}
+
+int intel_dp_compute_sdp_latency(struct intel_crtc_state *crtc_state,
+ bool assume_all_enabled)
+{
+ const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
+ int sdp_latency = 0;
+ int linetime_us;
+
+ linetime_us = DIV_ROUND_UP(adjusted_mode->crtc_htotal * 1000,
+ adjusted_mode->crtc_clock);
+ if (assume_all_enabled ||
+ crtc_state->infoframes.enable &
+ intel_hdmi_infoframe_enable(HDMI_PACKET_TYPE_GAMUT_METADATA))
+ sdp_latency = max(sdp_latency,
+
intel_dp_get_sdp_latency(HDMI_PACKET_TYPE_GAMUT_METADATA,
+ linetime_us));
+
+ if (assume_all_enabled || crtc_state->dsc.compression_enable)
+ sdp_latency = max(sdp_latency,
+ intel_dp_get_sdp_latency(DP_SDP_PPS,
linetime_us));
+
+ return sdp_latency;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
b/drivers/gpu/drm/i915/display/intel_dp.h
index f90cfd1dbbd0..bfd1bd448672 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -215,5 +215,6 @@ int intel_dp_compute_min_hblank(struct intel_crtc_state
*crtc_state,
int intel_dp_dsc_bpp_step_x16(const struct intel_connector *connector);
void intel_dp_dpcd_set_probe(struct intel_dp *intel_dp, bool
force_on_external);
bool intel_dp_in_hdr_mode(const struct drm_connector_state *conn_state);
+int intel_dp_compute_sdp_latency(struct intel_crtc_state *crtc_state, bool
assume_all_enabled);
#endif /* __INTEL_DP_H__ */
--
2.45.2
