[PATCH 22/30] drm/i915/dp: Enable DSC via the connector decompression AUX

Imre Deak imre.deak at intel.com
Fri Oct 27 14:41:22 UTC 2023


Enable DSC using the DSC AUX device stored for this purpose in the
connector. This prepares for a follow-up patch which toggles DSC for
each stream as needed, but for now keeps the current behavior, as DSC is
still only enabled for the first MST stream.

While at it set/clear only the DP_DECOMPRESSION_EN flag in the
DP_DSC_ENABLE DPCD register, preserving the reserved register bits.

v2:
- Add a helper function setting/clearing the decompression flag,
  preserving the reserved register bits.

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    | 14 ++++---
 drivers/gpu/drm/i915/display/intel_dp.c     | 46 +++++++++++++++++----
 drivers/gpu/drm/i915/display/intel_dp.h     |  2 +-
 drivers/gpu/drm/i915/display/intel_dp_mst.c |  4 +-
 4 files changed, 49 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index bbd7735e37150..68f899b3aa048 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2539,7 +2539,8 @@ static void mtl_ddi_pre_enable_dp(struct intel_atomic_state *state,
 
 	intel_dp_configure_protocol_converter(intel_dp, crtc_state);
 	if (!is_mst)
-		intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+		intel_dp_sink_set_decompression_state(to_intel_connector(conn_state->connector),
+						      crtc_state, true);
 
 	/*
 	 * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
@@ -2692,7 +2693,8 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
 
 	intel_dp_configure_protocol_converter(intel_dp, crtc_state);
 	if (!is_mst)
-		intel_dp_sink_set_decompression_state(intel_dp, crtc_state, true);
+		intel_dp_sink_set_decompression_state(to_intel_connector(conn_state->connector),
+						      crtc_state, true);
 	/*
 	 * DDI FEC: "anticipates enabling FEC encoding sets the FEC_READY bit
 	 * in the FEC_CONFIGURATION register to 1 before initiating link
@@ -2773,8 +2775,8 @@ static void hsw_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);
 	if (!is_mst)
-		intel_dp_sink_set_decompression_state(intel_dp, crtc_state,
-						      true);
+		intel_dp_sink_set_decompression_state(to_intel_connector(conn_state->connector),
+						      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) &&
@@ -3354,6 +3356,8 @@ static void intel_disable_ddi_dp(struct intel_atomic_state *state,
 				 const struct drm_connector_state *old_conn_state)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+	struct intel_connector *connector =
+		to_intel_connector(old_conn_state->connector);
 
 	intel_dp->link_trained = false;
 
@@ -3362,7 +3366,7 @@ static void intel_disable_ddi_dp(struct intel_atomic_state *state,
 	intel_psr_disable(intel_dp, old_crtc_state);
 	intel_edp_backlight_off(old_conn_state);
 	/* Disable the decompression in DP Sink */
-	intel_dp_sink_set_decompression_state(intel_dp, old_crtc_state,
+	intel_dp_sink_set_decompression_state(connector, old_crtc_state,
 					      false);
 	/* Disable Ignore_MSA bit in DP Sink */
 	intel_dp_sink_set_msa_timing_par_ignore_state(intel_dp, old_crtc_state,
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 2e92ead652756..24b196a78bb79 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2937,22 +2937,50 @@ static bool downstream_hpd_needs_d0(struct intel_dp *intel_dp)
 		intel_dp->downstream_ports[0] & DP_DS_PORT_HPD;
 }
 
-void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
+static int
+write_dsc_decompression_flag(struct drm_dp_aux *aux, u8 flag, bool set)
+{
+	int err;
+	u8 val;
+
+	err = drm_dp_dpcd_readb(aux, DP_DSC_ENABLE, &val);
+	if (err < 0)
+		return err;
+
+	if (set)
+		val |= flag;
+	else
+		val &= ~flag;
+
+	return drm_dp_dpcd_writeb(aux, DP_DSC_ENABLE, val);
+}
+
+static void
+intel_dp_sink_set_dsc_decompression(struct intel_connector *connector,
+				    bool enable)
+{
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+
+	if (write_dsc_decompression_flag(connector->dp.dsc_decompression_aux,
+					 DP_DECOMPRESSION_EN, enable) < 0)
+		drm_dbg_kms(&i915->drm,
+			    "Failed to %s sink decompression state\n",
+			    str_enable_disable(enable));
+}
+
+void intel_dp_sink_set_decompression_state(struct intel_connector *connector,
 					   const struct intel_crtc_state *crtc_state,
 					   bool enable)
 {
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-	int ret;
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
 
 	if (!crtc_state->dsc.compression_enable)
 		return;
 
-	ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_DSC_ENABLE,
-				 enable ? DP_DECOMPRESSION_EN : 0);
-	if (ret < 0)
-		drm_dbg_kms(&i915->drm,
-			    "Failed to %s sink decompression state\n",
-			    str_enable_disable(enable));
+	if (drm_WARN_ON(&i915->drm, !connector->dp.dsc_decompression_aux))
+		return;
+
+	intel_dp_sink_set_dsc_decompression(connector, enable);
 }
 
 static void
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 2080575fef69a..a231d234f6e9d 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -57,7 +57,7 @@ int intel_dp_retrain_link(struct intel_encoder *encoder,
 void intel_dp_set_power(struct intel_dp *intel_dp, u8 mode);
 void intel_dp_configure_protocol_converter(struct intel_dp *intel_dp,
 					   const struct intel_crtc_state *crtc_state);
-void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
+void intel_dp_sink_set_decompression_state(struct intel_connector *connector,
 					   const struct intel_crtc_state *crtc_state,
 					   bool enable);
 void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index b0310f464c1cd..8ef3a2611207c 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -735,7 +735,7 @@ static void intel_mst_disable_dp(struct intel_atomic_state *state,
 		 * 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);
+		intel_dp_sink_set_decompression_state(connector, old_crtc_state, false);
 }
 
 static void intel_mst_post_disable_dp(struct intel_atomic_state *state,
@@ -895,7 +895,7 @@ static void intel_mst_pre_enable_dp(struct intel_atomic_state *state,
 		 * 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);
+		intel_dp_sink_set_decompression_state(connector, pipe_config, true);
 		dig_port->base.pre_enable(state, &dig_port->base,
 						pipe_config, NULL);
 	}
-- 
2.39.2



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