drm/i915: add DP 1.2 MST support (v0.7)

This adds DP 1.2 MST support on Haswell systems.

Notes:
a) this reworks irq handling for DP MST ports, so that we can
avoid the mode config locking in the current hpd handlers, as
we need to process up/down msgs at a better time.

Changes since v0.1:
use PORT_PCH_HOTPLUG to detect short vs long pulses
add a workqueue to deal with digital events as they can get blocked on the
main workqueue beyong mode_config mutex
fix a bunch of modeset checker warnings
acks irqs in the driver
cleanup the MST encoders

Changes since v0.2:
check irq status again in work handler
move around bring up and tear down to fix DPMS on/off
use path properties.

Changes since v0.3:
updates for mst apis
more state checker fixes
irq handling improvements
fbcon handling support
improved reference counting of link - fixes redocking.

Changes since v0.4:
handle gpu reset hpd reinit without oopsing
check link status on HPD irqs
fix suspend/resume

Changes since v0.5:
use proper functions to get max link/lane counts
fix another checker backtrace - due to connectors disappearing.
set output type in more places fro, unknown->displayport
don't talk to devices if no HPD asserted
check mst on short irqs only
check link status properly
rebase onto prepping irq changes.
drop unsued force_act

Changes since v0.6:
cleanup unused struct entry.

[airlied: fix some sparse warnings].

Reviewed-by: Todd Previte <tprevite@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/Makefile

@@ -59,6 +59,7 @@ i915-y += dvo_ch7017.o \
 	  intel_crt.o \
 	  intel_ddi.o \
 	  intel_dp.o \
+	  intel_dp_mst.o \
 	  intel_dsi_cmd.o \
 	  intel_dsi.o \
 	  intel_dsi_pll.o \

drivers/gpu/drm/i915/i915_dma.c

@@ -1717,6 +1717,13 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 		goto out_mtrrfree;
 	}
 
+	dev_priv->dp_wq = alloc_ordered_workqueue("i915-dp", 0);
+	if (dev_priv->dp_wq == NULL) {
+		DRM_ERROR("Failed to create our dp workqueue.\n");
+		ret = -ENOMEM;
+		goto out_freewq;
+	}
+
 	intel_irq_init(dev);
 	intel_uncore_sanitize(dev);
 
@@ -1792,6 +1799,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	intel_teardown_gmbus(dev);
 	intel_teardown_mchbar(dev);
 	pm_qos_remove_request(&dev_priv->pm_qos);
+	destroy_workqueue(dev_priv->dp_wq);
+out_freewq:
 	destroy_workqueue(dev_priv->wq);
 out_mtrrfree:
 	arch_phys_wc_del(dev_priv->gtt.mtrr);
@@ -1892,6 +1901,7 @@ int i915_driver_unload(struct drm_device *dev)
 	intel_teardown_gmbus(dev);
 	intel_teardown_mchbar(dev);
 
+	destroy_workqueue(dev_priv->dp_wq);
 	destroy_workqueue(dev_priv->wq);
 	pm_qos_remove_request(&dev_priv->pm_qos);
 

drivers/gpu/drm/i915/i915_drv.c

@@ -518,7 +518,6 @@ static int i915_drm_freeze(struct drm_device *dev)
 
 		flush_delayed_work(&dev_priv->rps.delayed_resume_work);
 
-		intel_runtime_pm_disable_interrupts(dev);
 
 		intel_suspend_gt_powersave(dev);
 
@@ -532,6 +531,9 @@ static int i915_drm_freeze(struct drm_device *dev)
 		}
 		drm_modeset_unlock_all(dev);
 
+		intel_dp_mst_suspend(dev);
+		intel_runtime_pm_disable_interrupts(dev);
+
 		intel_modeset_suspend_hw(dev);
 	}
 
@@ -646,6 +648,15 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
 
 		intel_modeset_init_hw(dev);
 
+		{
+			unsigned long irqflags;
+			spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+			if (dev_priv->display.hpd_irq_setup)
+				dev_priv->display.hpd_irq_setup(dev);
+			spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+		}
+
+		intel_dp_mst_resume(dev);
 		drm_modeset_lock_all(dev);
 		intel_modeset_setup_hw_state(dev, true);
 		drm_modeset_unlock_all(dev);

drivers/gpu/drm/i915/i915_drv.h

@@ -1595,6 +1595,15 @@ struct drm_i915_private {
 	u32 short_hpd_port_mask;
 	struct work_struct dig_port_work;
 
+	/*
+	 * if we get a HPD irq from DP and a HPD irq from non-DP
+	 * the non-DP HPD could block the workqueue on a mode config
+	 * mutex getting, that userspace may have taken. However
+	 * userspace is waiting on the DP workqueue to run which is
+	 * blocked behind the non-DP one.
+	 */
+	struct workqueue_struct *dp_wq;
+
 	/* Old dri1 support infrastructure, beware the dragons ya fools entering
 	 * here! */
 	struct i915_dri1_state dri1;

drivers/gpu/drm/i915/i915_irq.c

@@ -1846,7 +1846,7 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev,
 	 * deadlock.
 	 */
 	if (queue_dig)
-		schedule_work(&dev_priv->dig_port_work);
+		queue_work(dev_priv->dp_wq, &dev_priv->dig_port_work);
 	if (queue_hp)
 		schedule_work(&dev_priv->hotplug_work);
 }
@@ -4739,7 +4739,9 @@ void intel_hpd_init(struct drm_device *dev)
 	list_for_each_entry(connector, &mode_config->connector_list, head) {
 		struct intel_connector *intel_connector = to_intel_connector(connector);
 		connector->polled = intel_connector->polled;
-		if (!connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE)
+		if (connector->encoder && !connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE)
+			connector->polled = DRM_CONNECTOR_POLL_HPD;
+		if (intel_connector->mst_port)
 			connector->polled = DRM_CONNECTOR_POLL_HPD;
 	}
 

drivers/gpu/drm/i915/intel_ddi.c

@@ -116,7 +116,10 @@ enum port intel_ddi_get_encoder_port(struct intel_encoder *intel_encoder)
 	struct drm_encoder *encoder = &intel_encoder->base;
 	int type = intel_encoder->type;
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP ||
+	if (type == INTEL_OUTPUT_DP_MST) {
+		struct intel_digital_port *intel_dig_port = enc_to_mst(encoder)->primary;
+		return intel_dig_port->port;
+	} else if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP ||
 	    type == INTEL_OUTPUT_HDMI || type == INTEL_OUTPUT_UNKNOWN) {
 		struct intel_digital_port *intel_dig_port =
 			enc_to_dig_port(encoder);
@@ -584,8 +587,8 @@ static int intel_ddi_calc_wrpll_link(struct drm_i915_private *dev_priv,
 	return (refclk * n * 100) / (p * r);
 }
 
-static void intel_ddi_clock_get(struct intel_encoder *encoder,
-				struct intel_crtc_config *pipe_config)
+void intel_ddi_clock_get(struct intel_encoder *encoder,
+			 struct intel_crtc_config *pipe_config)
 {
 	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
 	int link_clock = 0;
@@ -755,8 +758,7 @@ void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
 	int type = intel_encoder->type;
 	uint32_t temp;
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
-
+	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP || type == INTEL_OUTPUT_DP_MST) {
 		temp = TRANS_MSA_SYNC_CLK;
 		switch (intel_crtc->config.pipe_bpp) {
 		case 18:
@@ -778,6 +780,21 @@ void intel_ddi_set_pipe_settings(struct drm_crtc *crtc)
 	}
 }
 
+void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state)
+{
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum transcoder cpu_transcoder = intel_crtc->config.cpu_transcoder;
+	uint32_t temp;
+	temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+	if (state == true)
+		temp |= TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
+	else
+		temp &= ~TRANS_DDI_DP_VC_PAYLOAD_ALLOC;
+	I915_WRITE(TRANS_DDI_FUNC_CTL(cpu_transcoder), temp);
+}
+
 void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 {
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
@@ -857,7 +874,19 @@ void intel_ddi_enable_transcoder_func(struct drm_crtc *crtc)
 		   type == INTEL_OUTPUT_EDP) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
-		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
+		if (intel_dp->is_mst) {
+			temp |= TRANS_DDI_MODE_SELECT_DP_MST;
+		} else
+			temp |= TRANS_DDI_MODE_SELECT_DP_SST;
+
+		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
+	} else if (type == INTEL_OUTPUT_DP_MST) {
+		struct intel_dp *intel_dp = &enc_to_mst(encoder)->primary->dp;
+
+		if (intel_dp->is_mst) {
+			temp |= TRANS_DDI_MODE_SELECT_DP_MST;
+		} else
+			temp |= TRANS_DDI_MODE_SELECT_DP_SST;
 
 		temp |= DDI_PORT_WIDTH(intel_dp->lane_count);
 	} else {
@@ -874,7 +903,7 @@ void intel_ddi_disable_transcoder_func(struct drm_i915_private *dev_priv,
 	uint32_t reg = TRANS_DDI_FUNC_CTL(cpu_transcoder);
 	uint32_t val = I915_READ(reg);
 
-	val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK);
+	val &= ~(TRANS_DDI_FUNC_ENABLE | TRANS_DDI_PORT_MASK | TRANS_DDI_DP_VC_PAYLOAD_ALLOC);
 	val |= TRANS_DDI_PORT_NONE;
 	I915_WRITE(reg, val);
 }
@@ -913,8 +942,11 @@ bool intel_ddi_connector_get_hw_state(struct intel_connector *intel_connector)
 	case TRANS_DDI_MODE_SELECT_DP_SST:
 		if (type == DRM_MODE_CONNECTOR_eDP)
 			return true;
-	case TRANS_DDI_MODE_SELECT_DP_MST:
 		return (type == DRM_MODE_CONNECTOR_DisplayPort);
+	case TRANS_DDI_MODE_SELECT_DP_MST:
+		/* if the transcoder is in MST state then
+		 * connector isn't connected */
+		return false;
 
 	case TRANS_DDI_MODE_SELECT_FDI:
 		return (type == DRM_MODE_CONNECTOR_VGA);
@@ -966,6 +998,9 @@ bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
 
 			if ((tmp & TRANS_DDI_PORT_MASK)
 			    == TRANS_DDI_SELECT_PORT(port)) {
+				if ((tmp & TRANS_DDI_MODE_SELECT_MASK) == TRANS_DDI_MODE_SELECT_DP_MST)
+					return false;
+
 				*pipe = i;
 				return true;
 			}
@@ -1272,10 +1307,15 @@ void intel_ddi_prepare_link_retrain(struct drm_encoder *encoder)
 			intel_wait_ddi_buf_idle(dev_priv, port);
 	}
 
-	val = DP_TP_CTL_ENABLE | DP_TP_CTL_MODE_SST |
+	val = DP_TP_CTL_ENABLE |
 	      DP_TP_CTL_LINK_TRAIN_PAT1 | DP_TP_CTL_SCRAMBLE_DISABLE;
-	if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
-		val |= DP_TP_CTL_ENHANCED_FRAME_ENABLE;
+	if (intel_dp->is_mst)
+		val |= DP_TP_CTL_MODE_MST;
+	else {
+		val |= DP_TP_CTL_MODE_SST;
+		if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
+			val |= DP_TP_CTL_ENHANCED_FRAME_ENABLE;
+	}
 	I915_WRITE(DP_TP_CTL(port), val);
 	POSTING_READ(DP_TP_CTL(port));
 
@@ -1314,11 +1354,16 @@ void intel_ddi_fdi_disable(struct drm_crtc *crtc)
 
 static void intel_ddi_hot_plug(struct intel_encoder *intel_encoder)
 {
-	struct intel_dp *intel_dp = enc_to_intel_dp(&intel_encoder->base);
-	int type = intel_encoder->type;
+	struct intel_digital_port *intel_dig_port = enc_to_dig_port(&intel_encoder->base);
+	int type = intel_dig_port->base.type;
+
+	if (type != INTEL_OUTPUT_DISPLAYPORT &&
+	    type != INTEL_OUTPUT_EDP &&
+	    type != INTEL_OUTPUT_UNKNOWN) {
+		return;
+	}
 
-	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP)
-		intel_dp_check_link_status(intel_dp);
+	intel_dp_hot_plug(intel_encoder);
 }
 
 void intel_ddi_get_config(struct intel_encoder *encoder,

drivers/gpu/drm/i915/intel_display.c

@@ -101,6 +101,14 @@ static void haswell_set_pipeconf(struct drm_crtc *crtc);
 static void intel_set_pipe_csc(struct drm_crtc *crtc);
 static void vlv_prepare_pll(struct intel_crtc *crtc);
 
+static struct intel_encoder *intel_find_encoder(struct intel_connector *connector, int pipe)
+{
+	if (!connector->mst_port)
+		return connector->encoder;
+	else
+		return &connector->mst_port->mst_encoders[pipe]->base;
+}
+
 typedef struct {
 	int	min, max;
 } intel_range_t;
@@ -4130,6 +4138,9 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
 	if (intel_crtc->config.has_pch_encoder)
 		lpt_pch_enable(crtc);
 
+	if (intel_crtc->config.dp_encoder_is_mst)
+		intel_ddi_set_vc_payload_alloc(crtc, true);
+
 	for_each_encoder_on_crtc(dev, crtc, encoder) {
 		encoder->enable(encoder);
 		intel_opregion_notify_encoder(encoder, true);
@@ -4178,6 +4189,9 @@ static void ironlake_crtc_disable(struct drm_crtc *crtc)
 
 	intel_disable_pipe(dev_priv, pipe);
 
+	if (intel_crtc->config.dp_encoder_is_mst)
+		intel_ddi_set_vc_payload_alloc(crtc, false);
+
 	ironlake_pfit_disable(intel_crtc);
 
 	for_each_encoder_on_crtc(dev, crtc, encoder)
@@ -4336,6 +4350,9 @@ intel_display_port_power_domain(struct intel_encoder *intel_encoder)
 	case INTEL_OUTPUT_EDP:
 		intel_dig_port = enc_to_dig_port(&intel_encoder->base);
 		return port_to_power_domain(intel_dig_port->port);
+	case INTEL_OUTPUT_DP_MST:
+		intel_dig_port = enc_to_mst(&intel_encoder->base)->primary;
+		return port_to_power_domain(intel_dig_port->port);
 	case INTEL_OUTPUT_ANALOG:
 		return POWER_DOMAIN_PORT_CRT;
 	case INTEL_OUTPUT_DSI:
@@ -5004,6 +5021,10 @@ static void intel_connector_check_state(struct intel_connector *connector)
 			      connector->base.base.id,
 			      connector->base.name);
 
+		/* there is no real hw state for MST connectors */
+		if (connector->mst_port)
+			return;
+
 		WARN(connector->base.dpms == DRM_MODE_DPMS_OFF,
 		     "wrong connector dpms state\n");
 		WARN(connector->base.encoder != &encoder->base,
@@ -10524,6 +10545,14 @@ check_encoder_state(struct drm_device *dev)
 			if (connector->base.dpms != DRM_MODE_DPMS_OFF)
 				active = true;
 		}
+		/*
+		 * for MST connectors if we unplug the connector is gone
+		 * away but the encoder is still connected to a crtc
+		 * until a modeset happens in response to the hotplug.
+		 */
+		if (!enabled && encoder->base.encoder_type == DRM_MODE_ENCODER_DPMST)
+			continue;
+
 		WARN(!!encoder->base.crtc != enabled,
 		     "encoder's enabled state mismatch "
 		     "(expected %i, found %i)\n",
@@ -11069,7 +11098,7 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 		 * for them. */
 		for (ro = 0; ro < set->num_connectors; ro++) {
 			if (set->connectors[ro] == &connector->base) {
-				connector->new_encoder = connector->encoder;
+				connector->new_encoder = intel_find_encoder(connector, to_intel_crtc(set->crtc)->pipe);
 				break;
 			}
 		}
@@ -11115,7 +11144,7 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 					 new_crtc)) {
 			return -EINVAL;
 		}
-		connector->encoder->new_crtc = to_intel_crtc(new_crtc);
+		connector->new_encoder->new_crtc = to_intel_crtc(new_crtc);
 
 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 			connector->base.base.id,
@@ -11149,7 +11178,12 @@ intel_modeset_stage_output_state(struct drm_device *dev,
 		}
 	}
 	/* Now we've also updated encoder->new_crtc for all encoders. */
-
+	list_for_each_entry(connector, &dev->mode_config.connector_list,
+			    base.head) {
+		if (connector->new_encoder)
+			if (connector->new_encoder != connector->encoder)
+				connector->encoder = connector->new_encoder;
+	}
 	for_each_intel_crtc(dev, crtc) {
 		crtc->new_enabled = false;