[Intel-gfx] [PATCH 3/4] drm/i915/dp: Fix MST disable sequences

José Roberto de Souza jose.souza at intel.com
Sat Dec 7 01:18:31 UTC 2019


The disable sequence after wait for transcoder off was not correctly
implemented.
The MST disable sequence is basically the same for HSW, SKL, ICL and
TGL, with just minor changes for TGL.

So here calling a new MST function to do the MST sequences, most of
the steps just moved from the post disable hook.

With this last patch we finally fixed the hotplugs triggered by MST
sinks during the disable/enable sequence, those were causing source
to try to do a link training while it was not ready causing CPU pipe
FIFO underrrus on TGL.

BSpec: 4231
BSpec: 4163
BSpec: 22243
BSpec: 49190
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c     | 17 +++--
 drivers/gpu/drm/i915/display/intel_display.c |  2 +
 drivers/gpu/drm/i915/display/intel_dp_mst.c  | 79 ++++++++++++++++----
 drivers/gpu/drm/i915/display/intel_dp_mst.h  |  1 +
 4 files changed, 79 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index be5bc506d4d3..f06c6dfec888 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -34,6 +34,7 @@
 #include "intel_ddi.h"
 #include "intel_display_types.h"
 #include "intel_dp.h"
+#include "intel_dp_mst.h"
 #include "intel_dp_link_training.h"
 #include "intel_dpio_phy.h"
 #include "intel_dsi.h"
@@ -1953,17 +1954,19 @@ void intel_ddi_disable_transcoder_func(const struct intel_crtc_state *crtc_state
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
-	i915_reg_t reg = TRANS_DDI_FUNC_CTL(cpu_transcoder);
-	u32 val = I915_READ(reg);
+	u32 val;
+
+	val = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+	val &= ~TRANS_DDI_FUNC_ENABLE;
 
 	if (INTEL_GEN(dev_priv) >= 12) {
-		val &= ~(TRANS_DDI_FUNC_ENABLE | TGL_TRANS_DDI_PORT_MASK |
-			 TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
+		if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST) ||
+		    intel_dp_mst_is_slave_trans(crtc_state))
+			val &= ~TGL_TRANS_DDI_PORT_MASK;
 	} else {
-		val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK |
-			 TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
+		val &= ~TRANS_DDI_PORT_MASK;
 	}
-	I915_WRITE(reg, val);
+	I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), val);
 
 	if (dev_priv->quirks & QUIRK_INCREASE_DDI_DISABLED_TIME &&
 	    intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 2f74c0bfb2a8..d3eefb271fa4 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6776,6 +6776,8 @@ static void haswell_crtc_disable(struct intel_atomic_state *state,
 	if (!transcoder_is_dsi(cpu_transcoder))
 		intel_disable_pipe(old_crtc_state);
 
+	intel_dp_mst_post_trans_disabled(old_crtc_state);
+
 	if (INTEL_GEN(dev_priv) >= 11)
 		icl_disable_transcoder_port_sync(old_crtc_state);
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 49f1518e3ab9..3c98a25e6308 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -365,6 +365,57 @@ static void intel_mst_disable_dp(struct intel_encoder *encoder,
 					  old_crtc_state, old_conn_state);
 }
 
+static void
+dp_mst_post_trans_disabled(struct intel_encoder *encoder,
+			   const struct intel_crtc_state *old_crtc_state,
+			   const struct drm_connector_state *old_conn_state)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct intel_connector *connector =
+		to_intel_connector(old_conn_state->connector);
+	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	u32 val;
+
+	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+
+	val = I915_READ(TRANS_DDI_FUNC_CTL(old_crtc_state->cpu_transcoder));
+	val &= ~TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
+	I915_WRITE(TRANS_DDI_FUNC_CTL(old_crtc_state->cpu_transcoder), val);
+
+	if (intel_de_wait_for_set(dev_priv, intel_dp->regs.dp_tp_status,
+				  DP_TP_STATUS_ACT_SENT, 1))
+		DRM_ERROR("Timed out waiting for ACT sent when disabling\n");
+
+	drm_dp_check_act_status(&intel_dp->mst_mgr);
+
+	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, connector->port);
+}
+
+void
+intel_dp_mst_post_trans_disabled(const struct intel_crtc_state *old_crtc_state)
+{
+	struct drm_atomic_state *state = old_crtc_state->uapi.state;
+	struct drm_connector_state *old_conn_state;
+	struct drm_connector *conn;
+	int i;
+
+	if (!intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_DP_MST))
+		return;
+
+	for_each_old_connector_in_state(state, conn, old_conn_state, i) {
+		struct intel_encoder *encoder;
+
+		if (old_conn_state->crtc != old_crtc_state->uapi.crtc)
+			continue;
+
+		encoder = to_intel_encoder(old_conn_state->best_encoder);
+		dp_mst_post_trans_disabled(encoder, old_crtc_state,
+					   old_conn_state);
+	}
+}
+
 static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
 				      const struct intel_crtc_state *old_crtc_state,
 				      const struct drm_connector_state *old_conn_state)
@@ -383,6 +434,12 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
 	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
 		!intel_dp_mst_is_master_trans(old_crtc_state));
 
+	/*
+	 * Power down mst path before disabling the port, otherwise we end
+	 * up getting interrupts from the sink upon detecting link loss.
+	 */
+	drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port,
+				     false);
 	/*
 	 * From TGL spec: "If multi-stream slave transcoder: Configure
 	 * Transcoder Clock Select to direct no clock to the transcoder"
@@ -393,24 +450,20 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
 	if (INTEL_GEN(dev_priv) < 12 || !last_mst_stream)
 		intel_ddi_disable_pipe_clock(old_crtc_state);
 
-	/* this can fail */
-	drm_dp_check_act_status(&intel_dp->mst_mgr);
-	/* and this can also fail */
-	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
 
-	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, connector->port);
+	intel_mst->connector = NULL;
+	if (last_mst_stream) {
+		enum transcoder cpu_transcoder;
+		u32 val;
 
-	/*
-	 * Power down mst path before disabling the port, otherwise we end
-	 * up getting interrupts from the sink upon detecting link loss.
-	 */
-	drm_dp_send_power_updown_phy(&intel_dp->mst_mgr, connector->port,
-				     false);
+		cpu_transcoder = old_crtc_state->cpu_transcoder;
+		val = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+		val &= ~TGL_TRANS_DDI_PORT_MASK;
+		I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), val);
 
-	intel_mst->connector = NULL;
-	if (last_mst_stream)
 		intel_dig_port->base.post_disable(&intel_dig_port->base,
 						  old_crtc_state, NULL);
+	}
 
 	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
index e40767f78343..87f32fab90fc 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
@@ -16,5 +16,6 @@ void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
 int intel_dp_mst_encoder_active_links(struct intel_digital_port *intel_dig_port);
 bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state);
 bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
+void intel_dp_mst_post_trans_disabled(const struct intel_crtc_state *old_crtc_state);
 
 #endif /* __INTEL_DP_MST_H__ */
-- 
2.24.0



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