Merge tag 'topic/nouveau-i915-dp-helpers-and-cleanup-2020-08-31-1' of...

Merge tag 'topic/nouveau-i915-dp-helpers-and-cleanup-2020-08-31-1' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

UAPI Changes:

None

Cross-subsystem Changes:

* Moves a bunch of miscellaneous DP code from the i915 driver into a set
  of shared DRM DP helpers

Core Changes:

* New DRM DP helpers (see above)

Driver Changes:

* Implements usage of the aforementioned DP helpers in the nouveau
  driver, along with some other various HPD related cleanup for nouveau
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/11e59ebdea7ee4f46803a21fe9b21443d2b9c401.camel@redhat.com

Documentation/devicetree/bindings/display/panel/panel-simple.yaml

@@ -29,6 +29,8 @@ properties:
     # compatible must be listed in alphabetical order, ordered by compatible.
     # The description in the comment is mandatory for each compatible.
 
+        # Ampire AM-1280800N3TZQW-T00H 10.1" WQVGA TFT LCD panel
+      - ampire,am-1280800n3tzqw-t00h
         # Ampire AM-480272H3TMQW-T01H 4.3" WQVGA TFT LCD panel
       - ampire,am-480272h3tmqw-t01h
         # Ampire AM-800480R3TMQW-A1H 7.0" WVGA TFT LCD panel

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

@@ -473,7 +473,7 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
  * help move buffers to and from VRAM.
  */
 static int amdgpu_move_blit(struct ttm_buffer_object *bo,
-			    bool evict, bool no_wait_gpu,
+			    bool evict,
 			    struct ttm_resource *new_mem,
 			    struct ttm_resource *old_mem)
 {
@@ -571,7 +571,7 @@ static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
 	}
 
 	/* blit VRAM to GTT */
-	r = amdgpu_move_blit(bo, evict, ctx->no_wait_gpu, &tmp_mem, old_mem);
+	r = amdgpu_move_blit(bo, evict, &tmp_mem, old_mem);
 	if (unlikely(r)) {
 		goto out_cleanup;
 	}
@@ -621,7 +621,7 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
 	}
 
 	/* copy to VRAM */
-	r = amdgpu_move_blit(bo, evict, ctx->no_wait_gpu, new_mem, old_mem);
+	r = amdgpu_move_blit(bo, evict, new_mem, old_mem);
 	if (unlikely(r)) {
 		goto out_cleanup;
 	}
@@ -710,7 +710,7 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
 		   new_mem->mem_type == TTM_PL_VRAM) {
 		r = amdgpu_move_ram_vram(bo, evict, ctx, new_mem);
 	} else {
-		r = amdgpu_move_blit(bo, evict, ctx->no_wait_gpu,
+		r = amdgpu_move_blit(bo, evict,
 				     new_mem, old_mem);
 	}
 

drivers/gpu/drm/bridge/lontium-lt9611.c

@@ -960,13 +960,13 @@ static const struct drm_bridge_funcs lt9611_bridge_funcs = {
 static int lt9611_parse_dt(struct device *dev,
 			   struct lt9611 *lt9611)
 {
-	lt9611->dsi0_node = of_graph_get_remote_node(dev->of_node, 1, -1);
+	lt9611->dsi0_node = of_graph_get_remote_node(dev->of_node, 0, -1);
 	if (!lt9611->dsi0_node) {
 		dev_err(lt9611->dev, "failed to get remote node for primary dsi\n");
 		return -ENODEV;
 	}
 
-	lt9611->dsi1_node = of_graph_get_remote_node(dev->of_node, 2, -1);
+	lt9611->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);
 
 	lt9611->ac_mode = of_property_read_bool(dev->of_node, "lt,ac-mode");
 

drivers/gpu/drm/drm_dp_helper.c

@@ -423,6 +423,133 @@ bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
 }
 EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
 
+static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK;
+
+	if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4)
+		port_count = 4;
+
+	return port_count;
+}
+
+static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
+					  u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	u8 dpcd_ext[6];
+	int ret;
+
+	/*
+	 * Prior to DP1.3 the bit represented by
+	 * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
+	 * If it is set DP_DPCD_REV at 0000h could be at a value less than
+	 * the true capability of the panel. The only way to check is to
+	 * then compare 0000h and 2200h.
+	 */
+	if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
+	      DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
+		return 0;
+
+	ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext,
+			       sizeof(dpcd_ext));
+	if (ret < 0)
+		return ret;
+	if (ret != sizeof(dpcd_ext))
+		return -EIO;
+
+	if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
+		DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n",
+			      aux->name, dpcd[DP_DPCD_REV],
+			      dpcd_ext[DP_DPCD_REV]);
+		return 0;
+	}
+
+	if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
+		return 0;
+
+	DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
+		      aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+	memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
+
+	return 0;
+}
+
+/**
+ * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
+ * available
+ * @aux: DisplayPort AUX channel
+ * @dpcd: Buffer to store the resulting DPCD in
+ *
+ * Attempts to read the base DPCD caps for @aux. Additionally, this function
+ * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
+ * present.
+ *
+ * Returns: %0 if the DPCD was read successfully, negative error code
+ * otherwise.
+ */
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+			  u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	int ret;
+
+	ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
+	if (ret < 0)
+		return ret;
+	if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
+		return -EIO;
+
+	ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
+	if (ret < 0)
+		return ret;
+
+	DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
+		      aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
+
+/**
+ * drm_dp_read_downstream_info() - read DPCD downstream port info if available
+ * @aux: DisplayPort AUX channel
+ * @dpcd: A cached copy of the port's DPCD
+ * @downstream_ports: buffer to store the downstream port info in
+ *
+ * See also:
+ * drm_dp_downstream_max_clock()
+ * drm_dp_downstream_max_bpc()
+ *
+ * Returns: 0 if either the downstream port info was read successfully or
+ * there was no downstream info to read, or a negative error code otherwise.
+ */
+int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
+				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS])
+{
+	int ret;
+	u8 len;
+
+	memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS);
+
+	/* No downstream info to read */
+	if (!drm_dp_is_branch(dpcd) ||
+	    dpcd[DP_DPCD_REV] < DP_DPCD_REV_10 ||
+	    !(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
+		return 0;
+
+	len = drm_dp_downstream_port_count(dpcd);
+	if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE)
+		len *= 4;
+
+	ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len);
+	if (ret < 0)
+		return ret;
+
+	return ret == len ? 0 : -EIO;
+}
+EXPORT_SYMBOL(drm_dp_read_downstream_info);
+
 /**
  * drm_dp_downstream_max_clock() - extract branch device max
  *                                 pixel rate for legacy VGA
@@ -431,7 +558,11 @@ EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
  * @dpcd: DisplayPort configuration data
  * @port_cap: port capabilities
  *
- * Returns max clock in kHz on success or 0 if max clock not defined
+ * See also:
+ * drm_dp_read_downstream_info()
+ * drm_dp_downstream_max_bpc()
+ *
+ * Returns: Max clock in kHz on success or 0 if max clock not defined
  */
 int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 				const u8 port_cap[4])
@@ -462,7 +593,11 @@ EXPORT_SYMBOL(drm_dp_downstream_max_clock);
  * @dpcd: DisplayPort configuration data
  * @port_cap: port capabilities
  *
- * Returns max bpc on success or 0 if max bpc not defined
+ * See also:
+ * drm_dp_read_downstream_info()
+ * drm_dp_downstream_max_clock()
+ *
+ * Returns: Max bpc on success or 0 if max bpc not defined
  */
 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 			      const u8 port_cap[4])
@@ -668,6 +803,54 @@ void drm_dp_set_subconnector_property(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_dp_set_subconnector_property);
 
+/**
+ * drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink
+ * count
+ * @connector: The DRM connector to check
+ * @dpcd: A cached copy of the connector's DPCD RX capabilities
+ * @desc: A cached copy of the connector's DP descriptor
+ *
+ * See also: drm_dp_read_sink_count()
+ *
+ * Returns: %True if the (e)DP connector has a valid sink count that should
+ * be probed, %false otherwise.
+ */
+bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
+				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				const struct drm_dp_desc *desc)
+{
+	/* Some eDP panels don't set a valid value for the sink count */
+	return connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
+		dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 &&
+		dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT &&
+		!drm_dp_has_quirk(desc, 0, DP_DPCD_QUIRK_NO_SINK_COUNT);
+}
+EXPORT_SYMBOL(drm_dp_read_sink_count_cap);
+
+/**
+ * drm_dp_read_sink_count() - Retrieve the sink count for a given sink
+ * @aux: The DP AUX channel to use
+ *
+ * See also: drm_dp_read_sink_count_cap()
+ *
+ * Returns: The current sink count reported by @aux, or a negative error code
+ * otherwise.
+ */
+int drm_dp_read_sink_count(struct drm_dp_aux *aux)
+{
+	u8 count;
+	int ret;
+
+	ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count);
+	if (ret < 0)
+		return ret;
+	if (ret != 1)
+		return -EIO;
+
+	return DP_GET_SINK_COUNT(count);
+}
+EXPORT_SYMBOL(drm_dp_read_sink_count);
+
 /*
  * I2C-over-AUX implementation
  */

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -3486,6 +3486,28 @@ static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8  dp_link_count)
 	return dp_link_bw * dp_link_count / 2;
 }
 
+/**
+ * drm_dp_read_mst_cap() - check whether or not a sink supports MST
+ * @aux: The DP AUX channel to use
+ * @dpcd: A cached copy of the DPCD capabilities for this sink
+ *
+ * Returns: %True if the sink supports MST, %false otherwise
+ */
+bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
+			 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+	u8 mstm_cap;
+
+	if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
+		return false;
+
+	if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
+		return false;
+
+	return mstm_cap & DP_MST_CAP;
+}
+EXPORT_SYMBOL(drm_dp_read_mst_cap);
+
 /**
  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
  * @mgr: manager to set state for

drivers/gpu/drm/hisilicon/hibmc/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_HISI_HIBMC
 	tristate "DRM Support for Hisilicon Hibmc"
-	depends on DRM && PCI && MMU && ARM64
+	depends on DRM && PCI && ARM64
 	select DRM_KMS_HELPER
 	select DRM_VRAM_HELPER
 	select DRM_TTM

drivers/gpu/drm/i915/display/intel_dp.c

@@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder,
 	}
 }
 
-static void
-intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp)
-{
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-	u8 dpcd_ext[6];
-
-	/*
-	 * Prior to DP1.3 the bit represented by
-	 * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
-	 * if it is set DP_DPCD_REV at 0000h could be at a value less than
-	 * the true capability of the panel. The only way to check is to
-	 * then compare 0000h and 2200h.
-	 */
-	if (!(intel_dp->dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
-	      DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
-		return;
-
-	if (drm_dp_dpcd_read(&intel_dp->aux, DP_DP13_DPCD_REV,
-			     &dpcd_ext, sizeof(dpcd_ext)) != sizeof(dpcd_ext)) {
-		drm_err(&i915->drm,
-			"DPCD failed read at extended capabilities\n");
-		return;
-	}
-
-	if (intel_dp->dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
-		drm_dbg_kms(&i915->drm,
-			    "DPCD extended DPCD rev less than base DPCD rev\n");
-		return;
-	}
-
-	if (!memcmp(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext)))
-		return;
-
-	drm_dbg_kms(&i915->drm, "Base DPCD: %*ph\n",
-		    (int)sizeof(intel_dp->dpcd), intel_dp->dpcd);
-
-	memcpy(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext));
-}
-
-bool
-intel_dp_read_dpcd(struct intel_dp *intel_dp)
-{
-	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
-
-	if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd,
-			     sizeof(intel_dp->dpcd)) < 0)
-		return false; /* aux transfer failed */
-
-	intel_dp_extended_receiver_capabilities(intel_dp);
-
-	drm_dbg_kms(&i915->drm, "DPCD: %*ph\n", (int)sizeof(intel_dp->dpcd),
-		    intel_dp->dpcd);
-
-	return intel_dp->dpcd[DP_DPCD_REV] != 0;
-}
-
 bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
 {
 	u8 dprx = 0;
@@ -4563,7 +4507,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
 	/* this function is meant to be called only once */
 	drm_WARN_ON(&dev_priv->drm, intel_dp->dpcd[DP_DPCD_REV] != 0);
 
-	if (!intel_dp_read_dpcd(intel_dp))
+	if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd) != 0)
 		return false;
 
 	drm_dp_read_desc(&intel_dp->aux, &intel_dp->desc,
@@ -4634,11 +4578,23 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
 	return true;
 }
 
+static bool
+intel_dp_has_sink_count(struct intel_dp *intel_dp)
+{
+	if (!intel_dp->attached_connector)
+		return false;
+
+	return drm_dp_read_sink_count_cap(&intel_dp->attached_connector->base,
+					  intel_dp->dpcd,
+					  &intel_dp->desc);
+}
 
 static bool
 intel_dp_get_dpcd(struct intel_dp *intel_dp)
 {
-	if (!intel_dp_read_dpcd(intel_dp))
+	int ret;
+
+	if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd))
 		return false;
 
 	/*
@@ -4653,18 +4609,9 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
 		intel_dp_set_common_rates(intel_dp);
 	}
 
-	/*
-	 * Some eDP panels do not set a valid value for sink count, that is why
-	 * it don't care about read it here and in intel_edp_init_dpcd().
-	 */
-	if (!intel_dp_is_edp(intel_dp) &&
-	    !drm_dp_has_quirk(&intel_dp->desc, 0,
-			      DP_DPCD_QUIRK_NO_SINK_COUNT)) {
-		u8 count;
-		ssize_t r;
-
-		r = drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_COUNT, &count);
-		if (r < 1)
+	if (intel_dp_has_sink_count(intel_dp)) {
+		ret = drm_dp_read_sink_count(&intel_dp->aux);
+		if (ret < 0)
 			return false;
 
 		/*
@@ -4672,7 +4619,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
 		 * a member variable in intel_dp will track any changes
 		 * between short pulse interrupts.
 		 */
-		intel_dp->sink_count = DP_GET_SINK_COUNT(count);
+		intel_dp->sink_count = ret;
 
 		/*
 		 * SINK_COUNT == 0 and DOWNSTREAM_PORT_PRESENT == 1 implies that
@@ -4685,32 +4632,8 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp)
 			return false;
 	}
 
-	if (!drm_dp_is_branch(intel_dp->dpcd))
-		return true; /* native DP sink */
-
-	if (intel_dp->dpcd[DP_DPCD_REV] == 0x10)
-		return true; /* no per-port downstream info */
-
-	if (drm_dp_dpcd_read(&intel_dp->aux, DP_DOWNSTREAM_PORT_0,
-			     intel_dp->downstream_ports,
-			     DP_MAX_DOWNSTREAM_PORTS) < 0)
-		return false; /* downstream port status fetch failed */
-
-	return true;
-}
-
-static bool
-intel_dp_sink_can_mst(struct intel_dp *intel_dp)
-{
-	u8 mstm_cap;
-
-	if (intel_dp->dpcd[DP_DPCD_REV] < 0x12)
-		return false;
-
-	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_MSTM_CAP, &mstm_cap) != 1)
-		return false;
-
-	return mstm_cap & DP_MST_CAP;
+	return drm_dp_read_downstream_info(&intel_dp->aux, intel_dp->dpcd,
+					   intel_dp->downstream_ports) == 0;
 }
 
 static bool
@@ -4720,7 +4643,7 @@ intel_dp_can_mst(struct intel_dp *intel_dp)
 
 	return i915->params.enable_dp_mst &&
 		intel_dp->can_mst &&
-		intel_dp_sink_can_mst(intel_dp);
+		drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd);
 }
 
 static void
@@ -4729,7 +4652,7 @@ intel_dp_configure_mst(struct intel_dp *intel_dp)
 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
 	struct intel_encoder *encoder =
 		&dp_to_dig_port(intel_dp)->base;
-	bool sink_can_mst = intel_dp_sink_can_mst(intel_dp);
+	bool sink_can_mst = drm_dp_read_mst_cap(&intel_dp->aux, intel_dp->dpcd);
 
 	drm_dbg_kms(&i915->drm,
 		    "[ENCODER:%d:%s] MST support: port: %s, sink: %s, modparam: %s\n",
@@ -5963,9 +5886,8 @@ intel_dp_detect_dpcd(struct intel_dp *intel_dp)
 		return connector_status_connected;
 
 	/* If we're HPD-aware, SINK_COUNT changes dynamically */
-	if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11 &&
+	if (intel_dp_has_sink_count(intel_dp) &&
 	    intel_dp->downstream_ports[0] & DP_DS_PORT_HPD) {
-
 		return intel_dp->sink_count ?
 		connector_status_connected : connector_status_disconnected;
 	}

drivers/gpu/drm/i915/display/intel_dp.h

@@ -99,7 +99,6 @@ bool intel_dp_source_supports_hbr3(struct intel_dp *intel_dp);
 bool
 intel_dp_get_link_status(struct intel_dp *intel_dp, u8 *link_status);
 
-bool intel_dp_read_dpcd(struct intel_dp *intel_dp);
 bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp);
 int intel_dp_link_required(int pixel_clock, int bpp);
 int intel_dp_max_data_rate(int max_link_clock, int max_lanes);

drivers/gpu/drm/i915/display/intel_lspcon.c

@@ -571,7 +571,7 @@ bool lspcon_init(struct intel_digital_port *dig_port)
 		return false;
 	}
 
-	if (!intel_dp_read_dpcd(dp)) {
+	if (drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd) != 0) {
 		DRM_ERROR("LSPCON DPCD read failed\n");
 		return false;
 	}

drivers/gpu/drm/nouveau/dispnv04/dac.c

@@ -419,7 +419,7 @@ static void nv04_dac_commit(struct drm_encoder *encoder)
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
 	NV_DEBUG(drm, "Output %s is running on CRTC %d using output %c\n",
-		 nouveau_encoder_connector_get(nv_encoder)->base.name,
+		 nv04_encoder_get_connector(nv_encoder)->base.name,
 		 nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
 

drivers/gpu/drm/nouveau/dispnv04/dfp.c

@@ -184,7 +184,8 @@ static bool nv04_dfp_mode_fixup(struct drm_encoder *encoder,
 				struct drm_display_mode *adjusted_mode)
 {
 	struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
-	struct nouveau_connector *nv_connector = nouveau_encoder_connector_get(nv_encoder);
+	struct nouveau_connector *nv_connector =
+		nv04_encoder_get_connector(nv_encoder);
 
 	if (!nv_connector->native_mode ||
 	    nv_connector->scaling_mode == DRM_MODE_SCALE_NONE ||
@@ -478,7 +479,7 @@ static void nv04_dfp_commit(struct drm_encoder *encoder)
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
 	NV_DEBUG(drm, "Output %s is running on CRTC %d using output %c\n",
-		 nouveau_encoder_connector_get(nv_encoder)->base.name,
+		 nv04_encoder_get_connector(nv_encoder)->base.name,
 		 nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
 
@@ -591,7 +592,7 @@ static void nv04_dfp_restore(struct drm_encoder *encoder)
 
 	if (nv_encoder->dcb->type == DCB_OUTPUT_LVDS) {
 		struct nouveau_connector *connector =
-			nouveau_encoder_connector_get(nv_encoder);
+			nv04_encoder_get_connector(nv_encoder);
 
 		if (connector && connector->native_mode)
 			call_lvds_script(dev, nv_encoder->dcb, head,

drivers/gpu/drm/nouveau/dispnv04/disp.c

@@ -35,9 +35,28 @@
 
 #include <nvif/if0004.h>
 
+struct nouveau_connector *
+nv04_encoder_get_connector(struct nouveau_encoder *encoder)
+{
+	struct drm_device *dev = to_drm_encoder(encoder)->dev;
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+	struct nouveau_connector *nv_connector = NULL;
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		if (connector->encoder == to_drm_encoder(encoder))
+			nv_connector = nouveau_connector(connector);
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	return nv_connector;
+}
+
 static void
-nv04_display_fini(struct drm_device *dev, bool suspend)
+nv04_display_fini(struct drm_device *dev, bool runtime, bool suspend)
 {
+	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nv04_display *disp = nv04_display(dev);
 	struct drm_crtc *crtc;
 
@@ -49,6 +68,9 @@ nv04_display_fini(struct drm_device *dev, bool suspend)
 	if (nv_two_heads(dev))
 		NVWriteCRTC(dev, 1, NV_PCRTC_INTR_EN_0, 0);
 
+	if (!runtime)
+		cancel_work_sync(&drm->hpd_work);
+
 	if (!suspend)
 		return;
 

drivers/gpu/drm/nouveau/dispnv04/disp.h

@@ -6,6 +6,8 @@
 
 #include "nouveau_display.h"
 
+struct nouveau_encoder;
+
 enum nv04_fp_display_regs {
 	FP_DISPLAY_END,
 	FP_TOTAL,
@@ -93,6 +95,8 @@ nv04_display(struct drm_device *dev)
 
 /* nv04_display.c */
 int nv04_display_create(struct drm_device *);
+struct nouveau_connector *
+nv04_encoder_get_connector(struct nouveau_encoder *nv_encoder);
 
 /* nv04_crtc.c */
 int nv04_crtc_create(struct drm_device *, int index);

drivers/gpu/drm/nouveau/dispnv04/tvnv04.c

@@ -172,7 +172,7 @@ static void nv04_tv_commit(struct drm_encoder *encoder)
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
 	NV_DEBUG(drm, "Output %s is running on CRTC %d using output %c\n",
-		 nouveau_encoder_connector_get(nv_encoder)->base.name,
+		 nv04_encoder_get_connector(nv_encoder)->base.name,
 		 nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
 

drivers/gpu/drm/nouveau/dispnv04/tvnv17.c

@@ -599,7 +599,7 @@ static void nv17_tv_commit(struct drm_encoder *encoder)
 	helper->dpms(encoder, DRM_MODE_DPMS_ON);
 
 	NV_INFO(drm, "Output %s is running on CRTC %d using output %c\n",
-		nouveau_encoder_connector_get(nv_encoder)->base.name,
+		nv04_encoder_get_connector(nv_encoder)->base.name,
 		nv_crtc->index, '@' + ffs(nv_encoder->dcb->or));
 }
 

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -391,20 +391,6 @@ find_encoder(struct drm_connector *connector, int type)
 	return NULL;
 }
 
-struct nouveau_connector *
-nouveau_encoder_connector_get(struct nouveau_encoder *encoder)
-{
-	struct drm_device *dev = to_drm_encoder(encoder)->dev;
-	struct drm_connector *drm_connector;
-
-	list_for_each_entry(drm_connector, &dev->mode_config.connector_list, head) {
-		if (drm_connector->encoder == to_drm_encoder(encoder))
-			return nouveau_connector(drm_connector);
-	}
-
-	return NULL;
-}
-
 static void
 nouveau_connector_destroy(struct drm_connector *connector)
 {
@@ -435,7 +421,8 @@ nouveau_connector_ddc_detect(struct drm_connector *connector)
 
 		switch (nv_encoder->dcb->type) {
 		case DCB_OUTPUT_DP:
-			ret = nouveau_dp_detect(nv_encoder);
+			ret = nouveau_dp_detect(nouveau_connector(connector),
+						nv_encoder);
 			if (ret == NOUVEAU_DP_MST)
 				return NULL;
 			else if (ret == NOUVEAU_DP_SST)
@@ -541,6 +528,17 @@ nouveau_connector_set_encoder(struct drm_connector *connector,
 	}
 }
 
+static void
+nouveau_connector_set_edid(struct nouveau_connector *nv_connector,
+			   struct edid *edid)
+{
+	struct edid *old_edid = nv_connector->edid;
+
+	drm_connector_update_edid_property(&nv_connector->base, edid);
+	kfree(old_edid);
+	nv_connector->edid = edid;
+}
+
 static enum drm_connector_status
 nouveau_connector_detect(struct drm_connector *connector, bool force)
 {
@@ -554,13 +552,6 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 	int ret;
 	enum drm_connector_status conn_status = connector_status_disconnected;
 
-	/* Cleanup the previous EDID block. */
-	if (nv_connector->edid) {
-		drm_connector_update_edid_property(connector, NULL);
-		kfree(nv_connector->edid);
-		nv_connector->edid = NULL;
-	}
-
 	/* Outputs are only polled while runtime active, so resuming the
 	 * device here is unnecessary (and would deadlock upon runtime suspend
 	 * because it waits for polling to finish). We do however, want to
@@ -573,22 +564,23 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 		ret = pm_runtime_get_sync(dev->dev);
 		if (ret < 0 && ret != -EACCES) {
 			pm_runtime_put_autosuspend(dev->dev);
+			nouveau_connector_set_edid(nv_connector, NULL);
 			return conn_status;
 		}
 	}
 
 	nv_encoder = nouveau_connector_ddc_detect(connector);
 	if (nv_encoder && (i2c = nv_encoder->i2c) != NULL) {
+		struct edid *new_edid;
+
 		if ((vga_switcheroo_handler_flags() &
 		     VGA_SWITCHEROO_CAN_SWITCH_DDC) &&
 		    nv_connector->type == DCB_CONNECTOR_LVDS)
-			nv_connector->edid = drm_get_edid_switcheroo(connector,
-								     i2c);
+			new_edid = drm_get_edid_switcheroo(connector, i2c);
 		else
-			nv_connector->edid = drm_get_edid(connector, i2c);
+			new_edid = drm_get_edid(connector, i2c);
 
-		drm_connector_update_edid_property(connector,
-							nv_connector->edid);
+		nouveau_connector_set_edid(nv_connector, new_edid);
 		if (!nv_connector->edid) {
 			NV_ERROR(drm, "DDC responded, but no EDID for %s\n",
 				 connector->name);
@@ -622,6 +614,8 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 		conn_status = connector_status_connected;
 		drm_dp_cec_set_edid(&nv_connector->aux, nv_connector->edid);
 		goto out;
+	} else {
+		nouveau_connector_set_edid(nv_connector, NULL);
 	}
 
 	nv_encoder = nouveau_connector_of_detect(connector);
@@ -646,10 +640,11 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 			conn_status = connector_status_connected;
 			goto out;
 		}
-
 	}
 
  out:
+	if (!nv_connector->edid)
+		drm_dp_cec_unset_edid(&nv_connector->aux);
 
 	pm_runtime_mark_last_busy(dev->dev);
 	pm_runtime_put_autosuspend(dev->dev);
@@ -664,18 +659,12 @@ nouveau_connector_detect_lvds(struct drm_connector *connector, bool force)
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nouveau_connector *nv_connector = nouveau_connector(connector);
 	struct nouveau_encoder *nv_encoder = NULL;
+	struct edid *edid = NULL;
 	enum drm_connector_status status = connector_status_disconnected;
 
-	/* Cleanup the previous EDID block. */
-	if (nv_connector->edid) {
-		drm_connector_update_edid_property(connector, NULL);
-		kfree(nv_connector->edid);
-		nv_connector->edid = NULL;
-	}
-
 	nv_encoder = find_encoder(connector, DCB_OUTPUT_LVDS);
 	if (!nv_encoder)
-		return connector_status_disconnected;
+		goto out;
 
 	/* Try retrieving EDID via DDC */
 	if (!drm->vbios.fp_no_ddc) {
@@ -694,7 +683,8 @@ nouveau_connector_detect_lvds(struct drm_connector *connector, bool force)
 	 * valid - it's not (rh#613284)
 	 */
 	if (nv_encoder->dcb->lvdsconf.use_acpi_for_edid) {
-		if ((nv_connector->edid = nouveau_acpi_edid(dev, connector))) {
+		edid = nouveau_acpi_edid(dev, connector);
+		if (edid) {
 			status = connector_status_connected;
 			goto out;
 		}
@@ -714,12 +704,10 @@ nouveau_connector_detect_lvds(struct drm_connector *connector, bool force)
 	 * stored for the panel stored in them.
 	 */
 	if (!drm->vbios.fp_no_ddc) {
-		struct edid *edid =
-			(struct edid *)nouveau_bios_embedded_edid(dev);
+		edid = (struct edid *)nouveau_bios_embedded_edid(dev);
 		if (edid) {
-			nv_connector->edid =
-					kmemdup(edid, EDID_LENGTH, GFP_KERNEL);
-			if (nv_connector->edid)
+			edid = kmemdup(edid, EDID_LENGTH, GFP_KERNEL);
+			if (edid)
 				status = connector_status_connected;
 		}
 	}
@@ -732,7 +720,7 @@ nouveau_connector_detect_lvds(struct drm_connector *connector, bool force)
 		status = connector_status_unknown;
 #endif
 
-	drm_connector_update_edid_property(connector, nv_connector->edid);
+	nouveau_connector_set_edid(nv_connector, edid);
 	nouveau_connector_set_encoder(connector, nv_encoder);
 	return status;
 }
@@ -1150,59 +1138,39 @@ nouveau_connector_funcs_lvds = {
 	.early_unregister = nouveau_connector_early_unregister,
 };
 
+void
+nouveau_connector_hpd(struct drm_connector *connector)
+{
+	struct nouveau_drm *drm = nouveau_drm(connector->dev);
+	u32 mask = drm_connector_mask(connector);
+
+	mutex_lock(&drm->hpd_lock);
+	if (!(drm->hpd_pending & mask)) {
+		drm->hpd_pending |= mask;
+		schedule_work(&drm->hpd_work);
+	}
+	mutex_unlock(&drm->hpd_lock);
+}
+
 static int
 nouveau_connector_hotplug(struct nvif_notify *notify)
 {
 	struct nouveau_connector *nv_connector =
 		container_of(notify, typeof(*nv_connector), hpd);
 	struct drm_connector *connector = &nv_connector->base;
-	struct nouveau_drm *drm = nouveau_drm(connector->dev);
+	struct drm_device *dev = connector->dev;
+	struct nouveau_drm *drm = nouveau_drm(dev);
 	const struct nvif_notify_conn_rep_v0 *rep = notify->data;
-	const char *name = connector->name;
-	struct nouveau_encoder *nv_encoder;
-	int ret;
 	bool plugged = (rep->mask != NVIF_NOTIFY_CONN_V0_UNPLUG);
 
 	if (rep->mask & NVIF_NOTIFY_CONN_V0_IRQ) {
-		NV_DEBUG(drm, "service %s\n", name);
-		drm_dp_cec_irq(&nv_connector->aux);
-		if ((nv_encoder = find_encoder(connector, DCB_OUTPUT_DP)))
-			nv50_mstm_service(nv_encoder->dp.mstm);
-
-		return NVIF_NOTIFY_KEEP;
-	}
-
-	ret = pm_runtime_get(drm->dev->dev);
-	if (ret == 0) {
-		/* We can't block here if there's a pending PM request
-		 * running, as we'll deadlock nouveau_display_fini() when it
-		 * calls nvif_put() on our nvif_notify struct. So, simply
-		 * defer the hotplug event until the device finishes resuming
-		 */
-		NV_DEBUG(drm, "Deferring HPD on %s until runtime resume\n",
-			 name);
-		schedule_work(&drm->hpd_work);
-
-		pm_runtime_put_noidle(drm->dev->dev);
+		nouveau_dp_irq(drm, nv_connector);
 		return NVIF_NOTIFY_KEEP;
-	} else if (ret != 1 && ret != -EACCES) {
-		NV_WARN(drm, "HPD on %s dropped due to RPM failure: %d\n",
-			name, ret);
-		return NVIF_NOTIFY_DROP;
-	}
-
-	if (!plugged)
-		drm_dp_cec_unset_edid(&nv_connector->aux);
-	NV_DEBUG(drm, "%splugged %s\n", plugged ? "" : "un", name);
-	if ((nv_encoder = find_encoder(connector, DCB_OUTPUT_DP))) {
-		if (!plugged)
-			nv50_mstm_remove(nv_encoder->dp.mstm);
 	}
 
-	drm_helper_hpd_irq_event(connector->dev);
+	NV_DEBUG(drm, "%splugged %s\n", plugged ? "" : "un", connector->name);
+	nouveau_connector_hpd(connector);
 
-	pm_runtime_mark_last_busy(drm->dev->dev);
-	pm_runtime_put_autosuspend(drm->dev->dev);
 	return NVIF_NOTIFY_KEEP;
 }
 

drivers/gpu/drm/nouveau/nouveau_connector.h

@@ -187,6 +187,7 @@ nouveau_crtc_connector_get(struct nouveau_crtc *nv_crtc)
 
 struct drm_connector *
 nouveau_connector_create(struct drm_device *, const struct dcb_output *);
+void nouveau_connector_hpd(struct drm_connector *connector);
 
 extern int nouveau_tv_disable;
 extern int nouveau_ignorelid;

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -457,16 +457,70 @@ static struct nouveau_drm_prop_enum_list dither_depth[] = {
 	}                                                                      \
 } while(0)
 
+void
+nouveau_display_hpd_resume(struct drm_device *dev)
+{
+	struct nouveau_drm *drm = nouveau_drm(dev);
+
+	mutex_lock(&drm->hpd_lock);
+	drm->hpd_pending = ~0;
+	mutex_unlock(&drm->hpd_lock);
+
+	schedule_work(&drm->hpd_work);
+}
+
 static void
 nouveau_display_hpd_work(struct work_struct *work)
 {
 	struct nouveau_drm *drm = container_of(work, typeof(*drm), hpd_work);
+	struct drm_device *dev = drm->dev;
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+	u32 pending;
+	bool changed = false;
+
+	pm_runtime_get_sync(dev->dev);
 
-	pm_runtime_get_sync(drm->dev->dev);
+	mutex_lock(&drm->hpd_lock);
+	pending = drm->hpd_pending;
+	drm->hpd_pending = 0;
+	mutex_unlock(&drm->hpd_lock);
 
-	drm_helper_hpd_irq_event(drm->dev);
+	/* Nothing to do, exit early without updating the last busy counter */
+	if (!pending)
+		goto noop;
+
+	mutex_lock(&dev->mode_config.mutex);
+	drm_connector_list_iter_begin(dev, &conn_iter);
+
+	nouveau_for_each_non_mst_connector_iter(connector, &conn_iter) {
+		enum drm_connector_status old_status = connector->status;
+		u64 old_epoch_counter = connector->epoch_counter;
+
+		if (!(pending & drm_connector_mask(connector)))
+			continue;
+
+		connector->status = drm_helper_probe_detect(connector, NULL,
+							    false);
+		if (old_epoch_counter == connector->epoch_counter)
+			continue;
+
+		changed = true;
+		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s (epoch counter %llu->%llu)\n",
+			    connector->base.id, connector->name,
+			    drm_get_connector_status_name(old_status),
+			    drm_get_connector_status_name(connector->status),
+			    old_epoch_counter, connector->epoch_counter);
+	}
+
+	drm_connector_list_iter_end(&conn_iter);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	if (changed)
+		drm_kms_helper_hotplug_event(dev);
 
 	pm_runtime_mark_last_busy(drm->dev->dev);
+noop:
 	pm_runtime_put_sync(drm->dev->dev);
 }
 
@@ -490,12 +544,11 @@ nouveau_display_acpi_ntfy(struct notifier_block *nb, unsigned long val,
 				 */
 				pm_runtime_put_autosuspend(drm->dev->dev);
 			} else if (ret == 0) {
-				/* This may be the only indication we receive
-				 * of a connector hotplug on a runtime
-				 * suspended GPU, schedule hpd_work to check.
+				/* We've started resuming the GPU already, so
+				 * it will handle scheduling a full reprobe
+				 * itself
 				 */
 				NV_DEBUG(drm, "ACPI requested connector reprobe\n");
-				schedule_work(&drm->hpd_work);
 				pm_runtime_put_noidle(drm->dev->dev);
 			} else {
 				NV_WARN(drm, "Dropped ACPI reprobe event due to RPM error: %d\n",
@@ -569,7 +622,7 @@ nouveau_display_fini(struct drm_device *dev, bool suspend, bool runtime)
 		cancel_work_sync(&drm->hpd_work);
 
 	drm_kms_helper_poll_disable(dev);
-	disp->fini(dev, suspend);
+	disp->fini(dev, runtime, suspend);
 }
 
 static void
@@ -686,6 +739,7 @@ nouveau_display_create(struct drm_device *dev)
 	}
 
 	INIT_WORK(&drm->hpd_work, nouveau_display_hpd_work);
+	mutex_init(&drm->hpd_lock);
 #ifdef CONFIG_ACPI
 	drm->acpi_nb.notifier_call = nouveau_display_acpi_ntfy;
 	register_acpi_notifier(&drm->acpi_nb);
@@ -705,9 +759,10 @@ void
 nouveau_display_destroy(struct drm_device *dev)
 {
 	struct nouveau_display *disp = nouveau_display(dev);
+	struct nouveau_drm *drm = nouveau_drm(dev);
 
 #ifdef CONFIG_ACPI
-	unregister_acpi_notifier(&nouveau_drm(dev)->acpi_nb);
+	unregister_acpi_notifier(&drm->acpi_nb);
 #endif
 
 	drm_kms_helper_poll_fini(dev);
@@ -719,6 +774,7 @@ nouveau_display_destroy(struct drm_device *dev)
 	nvif_disp_dtor(&disp->disp);
 
 	nouveau_drm(dev)->display = NULL;
+	mutex_destroy(&drm->hpd_lock);
 	kfree(disp);
 }
 

drivers/gpu/drm/nouveau/nouveau_display.h

@@ -18,7 +18,7 @@ struct nouveau_display {
 	void *priv;
 	void (*dtor)(struct drm_device *);
 	int  (*init)(struct drm_device *, bool resume, bool runtime);
-	void (*fini)(struct drm_device *, bool suspend);
+	void (*fini)(struct drm_device *, bool suspend, bool runtime);
 
 	struct nvif_disp disp;
 
@@ -45,6 +45,7 @@ nouveau_display(struct drm_device *dev)
 int  nouveau_display_create(struct drm_device *dev);
 void nouveau_display_destroy(struct drm_device *dev);
 int  nouveau_display_init(struct drm_device *dev, bool resume, bool runtime);
+void nouveau_display_hpd_resume(struct drm_device *dev);
 void nouveau_display_fini(struct drm_device *dev, bool suspend, bool runtime);
 int  nouveau_display_suspend(struct drm_device *dev, bool runtime);
 void nouveau_display_resume(struct drm_device *dev, bool runtime);

drivers/gpu/drm/nouveau/nouveau_dp.c

@@ -36,47 +36,120 @@ MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");
 static int nouveau_mst = 1;
 module_param_named(mst, nouveau_mst, int, 0400);
 
-static void
-nouveau_dp_probe_oui(struct drm_device *dev, struct nvkm_i2c_aux *aux, u8 *dpcd)
+static bool
+nouveau_dp_has_sink_count(struct drm_connector *connector,
+			  struct nouveau_encoder *outp)
 {
-	struct nouveau_drm *drm = nouveau_drm(dev);
-	u8 buf[3];
+	return drm_dp_read_sink_count_cap(connector, outp->dp.dpcd, &outp->dp.desc);
+}
 
-	if (!(dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_OUI_SUPPORT))
-		return;
+static enum drm_connector_status
+nouveau_dp_probe_dpcd(struct nouveau_connector *nv_connector,
+		      struct nouveau_encoder *outp)
+{
+	struct drm_connector *connector = &nv_connector->base;
+	struct drm_dp_aux *aux = &nv_connector->aux;
+	struct nv50_mstm *mstm = NULL;
+	enum drm_connector_status status = connector_status_disconnected;
+	int ret;
+	u8 *dpcd = outp->dp.dpcd;
+
+	ret = drm_dp_read_dpcd_caps(aux, dpcd);
+	if (ret < 0)
+		goto out;
+
+	ret = drm_dp_read_desc(aux, &outp->dp.desc, drm_dp_is_branch(dpcd));
+	if (ret < 0)
+		goto out;
+
+	if (nouveau_mst) {
+		mstm = outp->dp.mstm;
+		if (mstm)
+			mstm->can_mst = drm_dp_read_mst_cap(aux, dpcd);
+	}
 
-	if (!nvkm_rdaux(aux, DP_SINK_OUI, buf, 3))
-		NV_DEBUG(drm, "Sink OUI: %02hx%02hx%02hx\n",
-			     buf[0], buf[1], buf[2]);
+	if (nouveau_dp_has_sink_count(connector, outp)) {
+		ret = drm_dp_read_sink_count(aux);
+		if (ret < 0)
+			goto out;
 
-	if (!nvkm_rdaux(aux, DP_BRANCH_OUI, buf, 3))
-		NV_DEBUG(drm, "Branch OUI: %02hx%02hx%02hx\n",
-			     buf[0], buf[1], buf[2]);
+		outp->dp.sink_count = ret;
 
+		/*
+		 * Dongle connected, but no display. Don't bother reading
+		 * downstream port info
+		 */
+		if (!outp->dp.sink_count)
+			return connector_status_disconnected;
+	}
+
+	ret = drm_dp_read_downstream_info(aux, dpcd,
+					  outp->dp.downstream_ports);
+	if (ret < 0)
+		goto out;
+
+	status = connector_status_connected;
+out:
+	if (status != connector_status_connected) {
+		/* Clear any cached info */
+		outp->dp.sink_count = 0;
+	}
+	return status;
 }
 
 int
-nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
+nouveau_dp_detect(struct nouveau_connector *nv_connector,
+		  struct nouveau_encoder *nv_encoder)
 {
 	struct drm_device *dev = nv_encoder->base.base.dev;
 	struct nouveau_drm *drm = nouveau_drm(dev);
-	struct nvkm_i2c_aux *aux;
-	u8 dpcd[8];
-	int ret;
-
-	aux = nv_encoder->aux;
-	if (!aux)
-		return -ENODEV;
-
-	ret = nvkm_rdaux(aux, DP_DPCD_REV, dpcd, sizeof(dpcd));
-	if (ret)
-		return ret;
+	struct drm_connector *connector = &nv_connector->base;
+	struct nv50_mstm *mstm = nv_encoder->dp.mstm;
+	enum drm_connector_status status;
+	u8 *dpcd = nv_encoder->dp.dpcd;
+	int ret = NOUVEAU_DP_NONE;
+
+	/* If we've already read the DPCD on an eDP device, we don't need to
+	 * reread it as it won't change
+	 */
+	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP &&
+	    dpcd[DP_DPCD_REV] != 0)
+		return NOUVEAU_DP_SST;
 
-	nv_encoder->dp.link_bw = 27000 * dpcd[1];
-	nv_encoder->dp.link_nr = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
+	mutex_lock(&nv_encoder->dp.hpd_irq_lock);
+	if (mstm) {
+		/* If we're not ready to handle MST state changes yet, just
+		 * report the last status of the connector. We'll reprobe it
+		 * once we've resumed.
+		 */
+		if (mstm->suspended) {
+			if (mstm->is_mst)
+				ret = NOUVEAU_DP_MST;
+			else if (connector->status ==
+				 connector_status_connected)
+				ret = NOUVEAU_DP_SST;
+
+			goto out;
+		}
+	}
+
+	status = nouveau_dp_probe_dpcd(nv_connector, nv_encoder);
+	if (status == connector_status_disconnected)
+		goto out;
+
+	/* If we're in MST mode, we're done here */
+	if (mstm && mstm->can_mst && mstm->is_mst) {
+		ret = NOUVEAU_DP_MST;
+		goto out;
+	}
+
+	nv_encoder->dp.link_bw = 27000 * dpcd[DP_MAX_LINK_RATE];
+	nv_encoder->dp.link_nr =
+		dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
 
 	NV_DEBUG(drm, "display: %dx%d dpcd 0x%02x\n",
-		     nv_encoder->dp.link_nr, nv_encoder->dp.link_bw, dpcd[0]);
+		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw,
+		 dpcd[DP_DPCD_REV]);
 	NV_DEBUG(drm, "encoder: %dx%d\n",
 		 nv_encoder->dcb->dpconf.link_nr,
 		 nv_encoder->dcb->dpconf.link_bw);
@@ -89,21 +162,66 @@ nouveau_dp_detect(struct nouveau_encoder *nv_encoder)
 	NV_DEBUG(drm, "maximum: %dx%d\n",
 		 nv_encoder->dp.link_nr, nv_encoder->dp.link_bw);
 
-	nouveau_dp_probe_oui(dev, aux, dpcd);
-
-	ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, nouveau_mst);
-	if (ret == 1)
-		return NOUVEAU_DP_MST;
-	if (ret == 0)
-		return NOUVEAU_DP_SST;
+	if (mstm && mstm->can_mst) {
+		ret = nv50_mstm_detect(nv_encoder);
+		if (ret == 1) {
+			ret = NOUVEAU_DP_MST;
+			goto out;
+		} else if (ret != 0) {
+			goto out;
+		}
+	}
+	ret = NOUVEAU_DP_SST;
+
+out:
+	if (mstm && !mstm->suspended && ret != NOUVEAU_DP_MST)
+		nv50_mstm_remove(mstm);
+
+	mutex_unlock(&nv_encoder->dp.hpd_irq_lock);
 	return ret;
 }
 
+void nouveau_dp_irq(struct nouveau_drm *drm,
+		    struct nouveau_connector *nv_connector)
+{
+	struct drm_connector *connector = &nv_connector->base;
+	struct nouveau_encoder *outp = find_encoder(connector, DCB_OUTPUT_DP);
+	struct nv50_mstm *mstm;
+	int ret;
+	bool send_hpd = false;
+
+	if (!outp)
+		return;
+
+	mstm = outp->dp.mstm;
+	NV_DEBUG(drm, "service %s\n", connector->name);
+
+	mutex_lock(&outp->dp.hpd_irq_lock);
+
+	if (mstm && mstm->is_mst) {
+		if (!nv50_mstm_service(drm, nv_connector, mstm))
+			send_hpd = true;
+	} else {
+		drm_dp_cec_irq(&nv_connector->aux);
+
+		if (nouveau_dp_has_sink_count(connector, outp)) {
+			ret = drm_dp_read_sink_count(&nv_connector->aux);
+			if (ret != outp->dp.sink_count)
+				send_hpd = true;
+			if (ret >= 0)
+				outp->dp.sink_count = ret;
+		}
+	}
+
+	mutex_unlock(&outp->dp.hpd_irq_lock);
+
+	if (send_hpd)
+		nouveau_connector_hpd(connector);
+}
+
 /* TODO:
  * - Use the minimum possible BPC here, once we add support for the max bpc
  *   property.
- * - Validate the mode against downstream port caps (see
- *   drm_dp_downstream_max_clock())
  * - Validate against the DP caps advertised by the GPU (we don't check these
  *   yet)
  */
@@ -114,15 +232,19 @@ nv50_dp_mode_valid(struct drm_connector *connector,
 		   unsigned *out_clock)
 {
 	const unsigned min_clock = 25000;
-	unsigned max_clock, clock;
+	unsigned max_clock, ds_clock, clock;
 	enum drm_mode_status ret;
 
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE && !outp->caps.dp_interlace)
 		return MODE_NO_INTERLACE;
 
 	max_clock = outp->dp.link_nr * outp->dp.link_bw;
-	clock = mode->clock * (connector->display_info.bpc * 3) / 10;
+	ds_clock = drm_dp_downstream_max_clock(outp->dp.dpcd,
+					       outp->dp.downstream_ports);
+	if (ds_clock)
+		max_clock = min(max_clock, ds_clock);
 
+	clock = mode->clock * (connector->display_info.bpc * 3) / 10;
 	ret = nouveau_conn_mode_clock_valid(mode, min_clock, max_clock,
 					    &clock);
 	if (out_clock)

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -953,7 +953,7 @@ nouveau_pmops_resume(struct device *dev)
 	ret = nouveau_do_resume(drm_dev, false);
 
 	/* Monitors may have been connected / disconnected during suspend */
-	schedule_work(&nouveau_drm(drm_dev)->hpd_work);
+	nouveau_display_hpd_resume(drm_dev);
 
 	return ret;
 }
@@ -1036,7 +1036,7 @@ nouveau_pmops_runtime_resume(struct device *dev)
 	drm_dev->switch_power_state = DRM_SWITCH_POWER_ON;
 
 	/* Monitors may have been connected / disconnected during suspend */
-	schedule_work(&nouveau_drm(drm_dev)->hpd_work);
+	nouveau_display_hpd_resume(drm_dev);
 
 	return ret;
 }

drivers/gpu/drm/nouveau/nouveau_drv.h

@@ -198,6 +198,8 @@ struct nouveau_drm {
 	struct nvbios vbios;
 	struct nouveau_display *display;
 	struct work_struct hpd_work;
+	struct mutex hpd_lock;
+	u32 hpd_pending;
 	struct work_struct fbcon_work;
 	int fbcon_new_state;
 #ifdef CONFIG_ACPI

drivers/gpu/drm/nouveau/nouveau_encoder.h

@@ -33,6 +33,7 @@
 #include <drm/drm_dp_mst_helper.h>
 #include "dispnv04/disp.h"
 struct nv50_head_atom;
+struct nouveau_connector;
 
 #define NV_DPMS_CLEARED 0x80
 
@@ -64,6 +65,17 @@ struct nouveau_encoder {
 			struct nv50_mstm *mstm;
 			int link_nr;
 			int link_bw;
+
+			/* Protects DP state that needs to be accessed outside
+			 * connector reprobing contexts
+			 */
+			struct mutex hpd_irq_lock;
+
+			u8 dpcd[DP_RECEIVER_CAP_SIZE];
+			u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
+			struct drm_dp_desc desc;
+
+			u8 sink_count;
 		} dp;
 	};
 
@@ -77,6 +89,21 @@ struct nouveau_encoder {
 		       struct nv50_head_atom *, u8 proto, u8 depth);
 };
 
+struct nv50_mstm {
+	struct nouveau_encoder *outp;
+
+	struct drm_dp_mst_topology_mgr mgr;
+
+	/* Protected under nouveau_encoder->dp.hpd_irq_lock */
+	bool can_mst;
+	bool is_mst;
+	bool suspended;
+
+	bool modified;
+	bool disabled;
+	int links;
+};
+
 struct nouveau_encoder *
 find_encoder(struct drm_connector *connector, int type);
 
@@ -100,20 +127,29 @@ get_slave_funcs(struct drm_encoder *enc)
 
 /* nouveau_dp.c */
 enum nouveau_dp_status {
+	NOUVEAU_DP_NONE,
 	NOUVEAU_DP_SST,
 	NOUVEAU_DP_MST,
 };
 
-int nouveau_dp_detect(struct nouveau_encoder *);
+int nouveau_dp_detect(struct nouveau_connector *, struct nouveau_encoder *);
+void nouveau_dp_irq(struct nouveau_drm *drm,
+		    struct nouveau_connector *nv_connector);
 enum drm_mode_status nv50_dp_mode_valid(struct drm_connector *,
 					struct nouveau_encoder *,
 					const struct drm_display_mode *,
 					unsigned *clock);
 
 struct nouveau_connector *
-nouveau_encoder_connector_get(struct nouveau_encoder *encoder);
-
-int nv50_mstm_detect(struct nv50_mstm *, u8 dpcd[8], int allow);
-void nv50_mstm_remove(struct nv50_mstm *);
-void nv50_mstm_service(struct nv50_mstm *);
+nv50_outp_get_new_connector(struct nouveau_encoder *outp,
+			    struct drm_atomic_state *state);
+struct nouveau_connector *
+nv50_outp_get_old_connector(struct nouveau_encoder *outp,
+			    struct drm_atomic_state *state);
+
+int nv50_mstm_detect(struct nouveau_encoder *encoder);
+void nv50_mstm_remove(struct nv50_mstm *mstm);
+bool nv50_mstm_service(struct nouveau_drm *drm,
+		       struct nouveau_connector *nv_connector,
+		       struct nv50_mstm *mstm);
 #endif /* __NOUVEAU_ENCODER_H__ */

drivers/gpu/drm/panel/panel-raydium-rm67191.c

@@ -552,8 +552,7 @@ static int rad_panel_probe(struct mipi_dsi_device *dsi)
 	panel->dsi = dsi;
 
 	dsi->format = MIPI_DSI_FMT_RGB888;
-	dsi->mode_flags =  MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
-			   MIPI_DSI_CLOCK_NON_CONTINUOUS;
+	dsi->mode_flags =  MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO;
 
 	ret = of_property_read_u32(np, "video-mode", &video_mode);
 	if (!ret) {

drivers/gpu/drm/panel/panel-simple.c

@@ -659,6 +659,32 @@ static void panel_simple_shutdown(struct device *dev)
 	drm_panel_unprepare(&panel->base);
 }
 
+static const struct drm_display_mode ampire_am_1280800n3tzqw_t00h_mode = {
+	.clock = 71100,
+	.hdisplay = 1280,
+	.hsync_start = 1280 + 40,
+	.hsync_end = 1280 + 40 + 80,
+	.htotal = 1280 + 40 + 80 + 40,
+	.vdisplay = 800,
+	.vsync_start = 800 + 3,
+	.vsync_end = 800 + 3 + 10,
+	.vtotal = 800 + 3 + 10 + 10,
+	.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
+};
+
+static const struct panel_desc ampire_am_1280800n3tzqw_t00h = {
+	.modes = &ampire_am_1280800n3tzqw_t00h_mode,
+	.num_modes = 1,
+	.bpc = 6,
+	.size = {
+		.width = 217,
+		.height = 136,
+	},
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
+	.connector_type = DRM_MODE_CONNECTOR_LVDS,
+};
+
 static const struct drm_display_mode ampire_am_480272h3tmqw_t01h_mode = {
 	.clock = 9000,
 	.hdisplay = 480,
@@ -3052,7 +3078,7 @@ static const struct drm_display_mode ortustech_com43h4m85ulc_mode  = {
 static const struct panel_desc ortustech_com43h4m85ulc = {
 	.modes = &ortustech_com43h4m85ulc_mode,
 	.num_modes = 1,
-	.bpc = 8,
+	.bpc = 6,
 	.size = {
 		.width = 56,
 		.height = 93,
@@ -3875,6 +3901,9 @@ static const struct panel_desc arm_rtsm = {
 
 static const struct of_device_id platform_of_match[] = {
 	{
+		.compatible = "ampire,am-1280800n3tzqw-t00h",
+		.data = &ampire_am_1280800n3tzqw_t00h,
+	}, {
 		.compatible = "ampire,am-480272h3tmqw-t01h",
 		.data = &ampire_am_480272h3tmqw_t01h,
 	}, {

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -422,7 +422,6 @@ static int radeon_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_reso
  */
 struct radeon_ttm_tt {
 	struct ttm_dma_tt		ttm;
-	struct radeon_device		*rdev;
 	u64				offset;
 
 	uint64_t			userptr;
@@ -525,6 +524,7 @@ static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
 				   struct ttm_resource *bo_mem)
 {
 	struct radeon_ttm_tt *gtt = (void*)ttm;
+	struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
 	uint32_t flags = RADEON_GART_PAGE_VALID | RADEON_GART_PAGE_READ |
 		RADEON_GART_PAGE_WRITE;
 	int r;
@@ -541,7 +541,7 @@ static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
 	}
 	if (ttm->caching_state == tt_cached)
 		flags |= RADEON_GART_PAGE_SNOOP;
-	r = radeon_gart_bind(gtt->rdev, gtt->offset, ttm->num_pages,
+	r = radeon_gart_bind(rdev, gtt->offset, ttm->num_pages,
 			     ttm->pages, gtt->ttm.dma_address, flags);
 	if (r) {
 		DRM_ERROR("failed to bind %lu pages at 0x%08X\n",
@@ -554,8 +554,9 @@ static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
 static void radeon_ttm_backend_unbind(struct ttm_tt *ttm)
 {
 	struct radeon_ttm_tt *gtt = (void *)ttm;
+	struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
 
-	radeon_gart_unbind(gtt->rdev, gtt->offset, ttm->num_pages);
+	radeon_gart_unbind(rdev, gtt->offset, ttm->num_pages);
 
 	if (gtt->userptr)
 		radeon_ttm_tt_unpin_userptr(ttm);
@@ -594,7 +595,6 @@ static struct ttm_tt *radeon_ttm_tt_create(struct ttm_buffer_object *bo,
 		return NULL;
 	}
 	gtt->ttm.ttm.func = &radeon_backend_func;
-	gtt->rdev = rdev;
 	if (ttm_dma_tt_init(&gtt->ttm, bo, page_flags)) {
 		kfree(gtt);
 		return NULL;

drivers/gpu/drm/sun4i/sun4i_tcon.c

@@ -474,9 +474,7 @@ static void sun4i_tcon0_mode_set_lvds(struct sun4i_tcon *tcon,
 		     SUN4I_TCON0_BASIC2_V_TOTAL(mode->crtc_vtotal * 2) |
 		     SUN4I_TCON0_BASIC2_V_BACKPORCH(bp));
 
-	reg = SUN4I_TCON0_LVDS_IF_CLK_SEL_TCON0 |
-		SUN4I_TCON0_LVDS_IF_DATA_POL_NORMAL |
-		SUN4I_TCON0_LVDS_IF_CLK_POL_NORMAL;
+	reg = SUN4I_TCON0_LVDS_IF_CLK_SEL_TCON0;
 	if (sun4i_tcon_get_pixel_depth(encoder) == 24)
 		reg |= SUN4I_TCON0_LVDS_IF_BITWIDTH_24BITS;
 	else

drivers/gpu/drm/virtio/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_VIRTIO_GPU
 	tristate "Virtio GPU driver"
-	depends on DRM && VIRTIO && MMU
+	depends on DRM && VIRTIO && VIRTIO_MENU && MMU
 	select DRM_KMS_HELPER
 	select DRM_GEM_SHMEM_HELPER
 	select VIRTIO_DMA_SHARED_BUFFER

drivers/gpu/drm/vkms/vkms_composer.c

@@ -32,8 +32,6 @@ static uint32_t compute_crc(void *vaddr_out, struct vkms_composer *composer)
 			src_offset = composer->offset
 				     + (i * composer->pitch)
 				     + (j * composer->cpp);
-			/* XRGB format ignores Alpha channel */
-			bitmap_clear(vaddr_out + src_offset, 24, 8);
 			crc = crc32_le(crc, vaddr_out + src_offset,
 				       sizeof(u32));
 		}
@@ -42,27 +40,51 @@ static uint32_t compute_crc(void *vaddr_out, struct vkms_composer *composer)
 	return crc;
 }
 
+static u8 blend_channel(u8 src, u8 dst, u8 alpha)
+{
+	u32 pre_blend;
+	u8 new_color;
+
+	pre_blend = (src * 255 + dst * (255 - alpha));
+
+	/* Faster div by 255 */
+	new_color = ((pre_blend + ((pre_blend + 257) >> 8)) >> 8);
+
+	return new_color;
+}
+
+static void alpha_blending(const u8 *argb_src, u8 *argb_dst)
+{
+	u8 alpha;
+
+	alpha = argb_src[3];
+	argb_dst[0] = blend_channel(argb_src[0], argb_dst[0], alpha);
+	argb_dst[1] = blend_channel(argb_src[1], argb_dst[1], alpha);
+	argb_dst[2] = blend_channel(argb_src[2], argb_dst[2], alpha);
+	/* Opaque primary */
+	argb_dst[3] = 0xFF;
+}
+
 /**
  * blend - blend value at vaddr_src with value at vaddr_dst
  * @vaddr_dst: destination address
  * @vaddr_src: source address
- * @dest_composer: destination framebuffer's metadata
+ * @dst_composer: destination framebuffer's metadata
  * @src_composer: source framebuffer's metadata
  *
- * Blend value at vaddr_src with value at vaddr_dst.
- * Currently, this function write value of vaddr_src on value
- * at vaddr_dst using buffer's metadata to locate the new values
- * from vaddr_src and their destination at vaddr_dst.
- *
- * TODO: Use the alpha value to blend vaddr_src with vaddr_dst
- *	 instead of overwriting it.
+ * Blend the vaddr_src value with the vaddr_dst value using the pre-multiplied
+ * alpha blending equation, since DRM currently assumes that the pixel color
+ * values have already been pre-multiplied with the alpha channel values. See
+ * more drm_plane_create_blend_mode_property(). This function uses buffer's
+ * metadata to locate the new composite values at vaddr_dst.
  */
 static void blend(void *vaddr_dst, void *vaddr_src,
-		  struct vkms_composer *dest_composer,
+		  struct vkms_composer *dst_composer,
 		  struct vkms_composer *src_composer)
 {
 	int i, j, j_dst, i_dst;
 	int offset_src, offset_dst;
+	u8 *pixel_dst, *pixel_src;
 
 	int x_src = src_composer->src.x1 >> 16;
 	int y_src = src_composer->src.y1 >> 16;
@@ -77,15 +99,16 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 
 	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
 		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
-			offset_dst = dest_composer->offset
-				     + (i_dst * dest_composer->pitch)
-				     + (j_dst++ * dest_composer->cpp);
+			offset_dst = dst_composer->offset
+				     + (i_dst * dst_composer->pitch)
+				     + (j_dst++ * dst_composer->cpp);
 			offset_src = src_composer->offset
 				     + (i * src_composer->pitch)
 				     + (j * src_composer->cpp);
 
-			memcpy(vaddr_dst + offset_dst,
-			       vaddr_src + offset_src, sizeof(u32));
+			pixel_src = (u8 *)(vaddr_src + offset_src);
+			pixel_dst = (u8 *)(vaddr_dst + offset_dst);
+			alpha_blending(pixel_src, pixel_dst);
 		}
 		i_dst++;
 	}

drivers/gpu/drm/vkms/vkms_crtc.c

@@ -86,6 +86,11 @@ static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
 	struct vkms_output *output = &vkmsdev->output;
 	struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 
+	if (!READ_ONCE(vblank->enabled)) {
+		*vblank_time = ktime_get();
+		return true;
+	}
+
 	*vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
 
 	if (WARN_ON(*vblank_time == vblank->time))

include/drm/drm_dp_helper.h

@@ -1607,12 +1607,18 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
 	return drm_dp_dpcd_write(aux, offset, &value, 1);
 }
 
+int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
+			  u8 dpcd[DP_RECEIVER_CAP_SIZE]);
+
 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 				 u8 status[DP_LINK_STATUS_SIZE]);
 
 bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
 				    u8 real_edid_checksum);
 
+int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
+				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS]);
 int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 				const u8 port_cap[4]);
 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
@@ -1628,6 +1634,12 @@ void drm_dp_set_subconnector_property(struct drm_connector *connector,
 				      const u8 *dpcd,
 				      const u8 port_cap[4]);
 
+struct drm_dp_desc;
+bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
+				const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+				const struct drm_dp_desc *desc);
+int drm_dp_read_sink_count(struct drm_dp_aux *aux);
+
 void drm_dp_remote_aux_init(struct drm_dp_aux *aux);
 void drm_dp_aux_init(struct drm_dp_aux *aux);
 int drm_dp_aux_register(struct drm_dp_aux *aux);
@@ -1686,7 +1698,8 @@ enum drm_dp_quirk {
 	 * @DP_DPCD_QUIRK_NO_SINK_COUNT:
 	 *
 	 * The device does not set SINK_COUNT to a non-zero value.
-	 * The driver should ignore SINK_COUNT during detection.
+	 * The driver should ignore SINK_COUNT during detection. Note that
+	 * drm_dp_read_sink_count_cap() automatically checks for this quirk.
 	 */
 	DP_DPCD_QUIRK_NO_SINK_COUNT,
 	/**

include/drm/drm_dp_mst_helper.h

@@ -728,10 +728,9 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 
 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr);
 
-
+bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state);
 
-
 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);