[PATCH v4 22/32] drm/i915/dp_mst: Enable decompression in the sink from the MST encoder hooks

[Imre Deak]

Enable/disable the DSC decompression in the sink/branch from the MST
encoder hooks. This prepares for an upcoming patch toggling DSC for each
stream as needed, but for now keeps the current behavior, as DSC is only
enabled for the first MST stream.

Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c    | 12 ++++++++----
 drivers/gpu/drm/i915/display/intel_dp_mst.c | 15 ++++++++++++++-
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 24b343465f6f6..0ec212ead9f02 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2538,7 +2538,9 @@ static void mtl_ddi_pre_enable_dp(struct intel_atomic_state *state,
 		intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
 
 	intel_dp_configure_protocol_converter(intel_dp, crtc_state);
-	intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+	if (!is_mst)
+		intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+
 	/*
 	 * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
 	 * in the FEC_CONFIGURATION register to 1 before initiating link
@@ -2689,7 +2691,8 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
 		intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
 
 	intel_dp_configure_protocol_converter(intel_dp, crtc_state);
-	intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+	if (!is_mst)
+		intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
 	/*
 	 * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
 	 * in the FEC_CONFIGURATION register to 1 before initiating link
@@ -2769,8 +2772,9 @@ static void hsw_ddi_pre_enable_dp(struct intel_atomic_state *state,
 	if (!is_mst)
 		intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
 	intel_dp_configure_protocol_converter(intel_dp, crtc_state);
-	intel_dp_sink_set_decompression_state(intel_dp, crtc_state,
-					      true);
+	if (!is_mst)
+		intel_dp_sink_set_decompression_state(intel_dp, crtc_state,
+						      true);
 	intel_dp_sink_set_fec_ready(intel_dp, crtc_state, true);
 	intel_dp_start_link_train(intel_dp, crtc_state);
 	if ((port != PORT_A || DISPLAY_VER(dev_priv) >= 9) &&
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 94627ab271c7d..f970e25f57fec 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -747,6 +747,13 @@ static void intel_mst_disable_dp(struct intel_atomic_state *state,
 	drm_dp_remove_payload_part1(&intel_dp->mst_mgr, new_mst_state, new_payload);
 
 	intel_audio_codec_disable(encoder, old_crtc_state, old_conn_state);
+
+	if (intel_dp->active_mst_links == 1) /* last stream ? */
+		/*
+		 * TODO: disable decompression for all streams/in any MST ports, not
+		 * only in the first downstream branch device.
+		 */
+		intel_dp_sink_set_decompression_state(intel_dp, old_crtc_state, false);
 }
 
 static void intel_mst_post_disable_dp(struct intel_atomic_state *state,
@@ -901,9 +908,15 @@ static void intel_mst_pre_enable_dp(struct intel_atomic_state *state,
 
 	drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port, true);
 
-	if (first_mst_stream)
+	if (first_mst_stream) {
+		/*
+		 * TODO: enable decompression for all streams/in any MST ports, not
+		 * only in the first downstream branch device.
+		 */
+		intel_dp_sink_set_decompression_state(intel_dp, pipe_config, true);
 		dig_port->base.pre_enable(state, &dig_port->base,
 						pipe_config, NULL);
+	}
 
 	intel_dp->active_mst_links++;
 
-- 
2.39.2