1 files changed, 191 insertions, 193 deletions

diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index ac90118b9e7a..a89f38fd3218 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -29,7 +29,6 @@
 #include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
-#include <linux/iopoll.h>
 
 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
 #include <linux/stacktrace.h>
@@ -68,9 +67,6 @@ static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
 
 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
 
-static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
-				     int id, u8 start_slot, u8 num_slots);
-
 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
 				 struct drm_dp_mst_port *port,
 				 int offset, int size, u8 *bytes);
@@ -175,18 +171,30 @@ static const char *drm_dp_mst_sideband_tx_state_str(int state)
 	return sideband_reason_str[state];
 }
 
+static inline u8
+drm_dp_mst_get_ufp_num_at_lct_from_rad(u8 lct, const u8 *rad)
+{
+	int idx = (lct / 2) - 1;
+	int shift = (lct % 2) ? 0 : 4;
+	u8 ufp_num;
+
+	/* mst_primary, it's rad is unset*/
+	if (lct == 1)
+		return 0;
+
+	ufp_num = (rad[idx] >> shift) & 0xf;
+
+	return ufp_num;
+}
+
 static int
 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
 {
 	int i;
-	u8 unpacked_rad[16];
+	u8 unpacked_rad[16] = {};
 
-	for (i = 0; i < lct; i++) {
-		if (i % 2)
-			unpacked_rad[i] = rad[i / 2] >> 4;
-		else
-			unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
-	}
+	for (i = 0; i < lct; i++)
+		unpacked_rad[i] = drm_dp_mst_get_ufp_num_at_lct_from_rad(i + 1, rad);
 
 	/* TODO: Eventually add something to printk so we can format the rad
 	 * like this: 1.2.3
@@ -320,6 +328,9 @@ static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr
 	hdr->broadcast = (buf[idx] >> 7) & 0x1;
 	hdr->path_msg = (buf[idx] >> 6) & 0x1;
 	hdr->msg_len = buf[idx] & 0x3f;
+	if (hdr->msg_len < 1)		/* min space for body CRC */
+		return false;
+
 	idx++;
 	hdr->somt = (buf[idx] >> 7) & 0x1;
 	hdr->eomt = (buf[idx] >> 6) & 0x1;
@@ -2181,24 +2192,20 @@ static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, guid_t *guid)
 	guid_copy(&mstb->guid, guid);
 
 	if (!drm_dp_validate_guid(mstb->mgr, &mstb->guid)) {
+		struct drm_dp_aux *aux;
 		u8 buf[UUID_SIZE];
 
 		export_guid(buf, &mstb->guid);
 
-		if (mstb->port_parent) {
-			ret = drm_dp_send_dpcd_write(mstb->mgr,
-						     mstb->port_parent,
-						     DP_GUID, sizeof(buf), buf);
-		} else {
-			ret = drm_dp_dpcd_write(mstb->mgr->aux,
-						DP_GUID, buf, sizeof(buf));
-		}
-	}
+		if (mstb->port_parent)
+			aux = &mstb->port_parent->aux;
+		else
+			aux = mstb->mgr->aux;
 
-	if (ret < 16 && ret > 0)
-		return -EPROTO;
+		ret = drm_dp_dpcd_write_data(aux, DP_GUID, buf, sizeof(buf));
+	}
 
-	return ret == 16 ? 0 : ret;
+	return ret;
 }
 
 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
@@ -2282,7 +2289,7 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
 		port->cached_edid = drm_edid_read_ddc(port->connector,
 						      &port->aux.ddc);
 
-	drm_connector_register(port->connector);
+	drm_connector_dynamic_register(port->connector);
 	return;
 
 error:
@@ -2545,9 +2552,8 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
 	if (!mstb)
 		goto out;
 
-	for (i = 0; i < lct - 1; i++) {
-		int shift = (i % 2) ? 0 : 4;
-		int port_num = (rad[i / 2] >> shift) & 0xf;
+	for (i = 1; i < lct; i++) {
+		int port_num = drm_dp_mst_get_ufp_num_at_lct_from_rad(i + 1, rad);
 
 		list_for_each_entry(port, &mstb->ports, next) {
 			if (port->port_num == port_num) {
@@ -2734,14 +2740,13 @@ retry:
 	do {
 		tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
 
-		ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
-					&msg[offset],
-					tosend);
-		if (ret != tosend) {
-			if (ret == -EIO && retries < 5) {
-				retries++;
-				goto retry;
-			}
+		ret = drm_dp_dpcd_write_data(mgr->aux, regbase + offset,
+					     &msg[offset],
+					     tosend);
+		if (ret == -EIO && retries < 5) {
+			retries++;
+			goto retry;
+		} else if (ret < 0) {
 			drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
 
 			return -EIO;
@@ -3264,7 +3269,7 @@ EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
 static int drm_dp_create_payload_at_dfp(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_dp_mst_atomic_payload *payload)
 {
-	return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot,
+	return drm_dp_dpcd_write_payload(mgr->aux, payload->vcpi, payload->vc_start_slot,
 					 payload->time_slots);
 }
 
@@ -3295,7 +3300,7 @@ static void drm_dp_destroy_payload_at_remote_and_dfp(struct drm_dp_mst_topology_
 	}
 
 	if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_DFP)
-		drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0);
+		drm_dp_dpcd_write_payload(mgr->aux, payload->vcpi, payload->vc_start_slot, 0);
 }
 
 /**
@@ -3573,8 +3578,7 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
 }
 
 /**
- * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link
- * @mgr: The &drm_dp_mst_topology_mgr to use
+ * drm_dp_get_vc_payload_bw - get the VC payload BW for an MTP link
  * @link_rate: link rate in 10kbits/s units
  * @link_lane_count: lane count
  *
@@ -3585,17 +3589,12 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
  *
  * Returns the BW / timeslot value in 20.12 fixed point format.
  */
-fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
-				    int link_rate, int link_lane_count)
+fixed20_12 drm_dp_get_vc_payload_bw(int link_rate, int link_lane_count)
 {
 	int ch_coding_efficiency =
 		drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate));
 	fixed20_12 ret;
 
-	if (link_rate == 0 || link_lane_count == 0)
-		drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n",
-			    link_rate, link_lane_count);
-
 	/* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */
 	ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count,
 						  ch_coding_efficiency),
@@ -3620,7 +3619,7 @@ enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux,
 	if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
 		return DRM_DP_SST;
 
-	if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
+	if (drm_dp_dpcd_read_byte(aux, DP_MSTM_CAP, &mstm_cap) < 0)
 		return DRM_DP_SST;
 
 	if (mstm_cap & DP_MST_CAP)
@@ -3675,15 +3674,15 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 		mgr->mst_primary = mstb;
 		drm_dp_mst_topology_get_mstb(mgr->mst_primary);
 
-		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
-					 DP_MST_EN |
-					 DP_UP_REQ_EN |
-					 DP_UPSTREAM_IS_SRC);
+		ret = drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL,
+					     DP_MST_EN |
+					     DP_UP_REQ_EN |
+					     DP_UPSTREAM_IS_SRC);
 		if (ret < 0)
 			goto out_unlock;
 
 		/* Write reset payload */
-		drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f);
+		drm_dp_dpcd_clear_payload(mgr->aux);
 
 		drm_dp_mst_queue_probe_work(mgr);
 
@@ -3693,12 +3692,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 		mstb = mgr->mst_primary;
 		mgr->mst_primary = NULL;
 		/* this can fail if the device is gone */
-		drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
+		drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL, 0);
 		ret = 0;
 		mgr->payload_id_table_cleared = false;
 
-		memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv));
-		memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv));
+		mgr->reset_rx_state = true;
 	}
 
 out_unlock:
@@ -3760,8 +3758,8 @@ EXPORT_SYMBOL(drm_dp_mst_topology_queue_probe);
 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
 {
 	mutex_lock(&mgr->lock);
-	drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
-			   DP_MST_EN | DP_UPSTREAM_IS_SRC);
+	drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL,
+			       DP_MST_EN | DP_UPSTREAM_IS_SRC);
 	mutex_unlock(&mgr->lock);
 	flush_work(&mgr->up_req_work);
 	flush_work(&mgr->work);
@@ -3810,18 +3808,18 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
 		goto out_fail;
 	}
 
-	ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
-				 DP_MST_EN |
-				 DP_UP_REQ_EN |
-				 DP_UPSTREAM_IS_SRC);
+	ret = drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL,
+				     DP_MST_EN |
+				     DP_UP_REQ_EN |
+				     DP_UPSTREAM_IS_SRC);
 	if (ret < 0) {
 		drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
 		goto out_fail;
 	}
 
 	/* Some hubs forget their guids after they resume */
-	ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, buf, sizeof(buf));
-	if (ret != sizeof(buf)) {
+	ret = drm_dp_dpcd_read_data(mgr->aux, DP_GUID, buf, sizeof(buf));
+	if (ret < 0) {
 		drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
 		goto out_fail;
 	}
@@ -3856,6 +3854,11 @@ out_fail:
 }
 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
 
+static void reset_msg_rx_state(struct drm_dp_sideband_msg_rx *msg)
+{
+	memset(msg, 0, sizeof(*msg));
+}
+
 static bool
 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
 		      struct drm_dp_mst_branch **mstb)
@@ -3875,8 +3878,8 @@ drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
 		*mstb = NULL;
 
 	len = min(mgr->max_dpcd_transaction_bytes, 16);
-	ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
-	if (ret != len) {
+	ret = drm_dp_dpcd_read_data(mgr->aux, basereg, replyblock, len);
+	if (ret < 0) {
 		drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
 		return false;
 	}
@@ -3914,9 +3917,9 @@ drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
 	curreply = len;
 	while (replylen > 0) {
 		len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
-		ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
-				    replyblock, len);
-		if (ret != len) {
+		ret = drm_dp_dpcd_read_data(mgr->aux, basereg + curreply,
+					    replyblock, len);
+		if (ret < 0) {
 			drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
 				    len, ret);
 			return false;
@@ -3934,6 +3937,34 @@ drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
 	return true;
 }
 
+static int get_msg_request_type(u8 data)
+{
+	return data & 0x7f;
+}
+
+static bool verify_rx_request_type(struct drm_dp_mst_topology_mgr *mgr,
+				   const struct drm_dp_sideband_msg_tx *txmsg,
+				   const struct drm_dp_sideband_msg_rx *rxmsg)
+{
+	const struct drm_dp_sideband_msg_hdr *hdr = &rxmsg->initial_hdr;
+	const struct drm_dp_mst_branch *mstb = txmsg->dst;
+	int tx_req_type = get_msg_request_type(txmsg->msg[0]);
+	int rx_req_type = get_msg_request_type(rxmsg->msg[0]);
+	char rad_str[64];
+
+	if (tx_req_type == rx_req_type)
+		return true;
+
+	drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, rad_str, sizeof(rad_str));
+	drm_dbg_kms(mgr->dev,
+		    "Got unexpected MST reply, mstb: %p seqno: %d lct: %d rad: %s rx_req_type: %s (%02x) != tx_req_type: %s (%02x)\n",
+		    mstb, hdr->seqno, mstb->lct, rad_str,
+		    drm_dp_mst_req_type_str(rx_req_type), rx_req_type,
+		    drm_dp_mst_req_type_str(tx_req_type), tx_req_type);
+
+	return false;
+}
+
 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 {
 	struct drm_dp_sideband_msg_tx *txmsg;
@@ -3949,9 +3980,9 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 
 	/* find the message */
 	mutex_lock(&mgr->qlock);
+
 	txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
 					 struct drm_dp_sideband_msg_tx, next);
-	mutex_unlock(&mgr->qlock);
 
 	/* Were we actually expecting a response, and from this mstb? */
 	if (!txmsg || txmsg->dst != mstb) {
@@ -3960,6 +3991,15 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 		hdr = &msg->initial_hdr;
 		drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
 			    mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
+
+		mutex_unlock(&mgr->qlock);
+
+		goto out_clear_reply;
+	}
+
+	if (!verify_rx_request_type(mgr, txmsg, msg)) {
+		mutex_unlock(&mgr->qlock);
+
 		goto out_clear_reply;
 	}
 
@@ -3975,20 +4015,15 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 			    txmsg->reply.u.nak.nak_data);
 	}
 
-	memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
-	drm_dp_mst_topology_put_mstb(mstb);
-
-	mutex_lock(&mgr->qlock);
 	txmsg->state = DRM_DP_SIDEBAND_TX_RX;
 	list_del(&txmsg->next);
+
 	mutex_unlock(&mgr->qlock);
 
 	wake_up_all(&mgr->tx_waitq);
 
-	return 0;
-
 out_clear_reply:
-	memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
+	reset_msg_rx_state(msg);
 out:
 	if (mstb)
 		drm_dp_mst_topology_put_mstb(mstb);
@@ -3996,6 +4031,22 @@ out:
 	return 0;
 }
 
+static bool primary_mstb_probing_is_done(struct drm_dp_mst_topology_mgr *mgr)
+{
+	bool probing_done = false;
+
+	mutex_lock(&mgr->lock);
+
+	if (mgr->mst_primary && drm_dp_mst_topology_try_get_mstb(mgr->mst_primary)) {
+		probing_done = mgr->mst_primary->link_address_sent;
+		drm_dp_mst_topology_put_mstb(mgr->mst_primary);
+	}
+
+	mutex_unlock(&mgr->lock);
+
+	return probing_done;
+}
+
 static inline bool
 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
 			  struct drm_dp_pending_up_req *up_req)
@@ -4026,8 +4077,12 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
 
 	/* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
 	if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
-		dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
-		hotplug = true;
+		if (!primary_mstb_probing_is_done(mgr)) {
+			drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it.\n");
+		} else {
+			dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
+			hotplug = true;
+		}
 	}
 
 	drm_dp_mst_topology_put_mstb(mstb);
@@ -4070,16 +4125,20 @@ static void drm_dp_mst_up_req_work(struct work_struct *work)
 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 {
 	struct drm_dp_pending_up_req *up_req;
+	struct drm_dp_mst_branch *mst_primary;
+	int ret = 0;
 
 	if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
-		goto out;
+		goto out_clear_reply;
 
 	if (!mgr->up_req_recv.have_eomt)
 		return 0;
 
 	up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
-	if (!up_req)
-		return -ENOMEM;
+	if (!up_req) {
+		ret = -ENOMEM;
+		goto out_clear_reply;
+	}
 
 	INIT_LIST_HEAD(&up_req->next);
 
@@ -4090,16 +4149,26 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 		drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
 			    up_req->msg.req_type);
 		kfree(up_req);
-		goto out;
+		goto out_clear_reply;
+	}
+
+	mutex_lock(&mgr->lock);
+	mst_primary = mgr->mst_primary;
+	if (!mst_primary || !drm_dp_mst_topology_try_get_mstb(mst_primary)) {
+		mutex_unlock(&mgr->lock);
+		kfree(up_req);
+		goto out_clear_reply;
 	}
+	mutex_unlock(&mgr->lock);
 
-	drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
+	drm_dp_send_up_ack_reply(mgr, mst_primary, up_req->msg.req_type,
 				 false);
 
+	drm_dp_mst_topology_put_mstb(mst_primary);
+
 	if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
 		const struct drm_dp_connection_status_notify *conn_stat =
 			&up_req->msg.u.conn_stat;
-		bool handle_csn;
 
 		drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
 			    conn_stat->port_number,
@@ -4108,16 +4177,6 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 			    conn_stat->message_capability_status,
 			    conn_stat->input_port,
 			    conn_stat->peer_device_type);
-
-		mutex_lock(&mgr->probe_lock);
-		handle_csn = mgr->mst_primary->link_address_sent;
-		mutex_unlock(&mgr->probe_lock);
-
-		if (!handle_csn) {
-			drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it.");
-			kfree(up_req);
-			goto out;
-		}
 	} else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
 		const struct drm_dp_resource_status_notify *res_stat =
 			&up_req->msg.u.resource_stat;
@@ -4132,10 +4191,20 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 	list_add_tail(&up_req->next, &mgr->up_req_list);
 	mutex_unlock(&mgr->up_req_lock);
 	queue_work(system_long_wq, &mgr->up_req_work);
+out_clear_reply:
+	reset_msg_rx_state(&mgr->up_req_recv);
+	return ret;
+}
 
-out:
-	memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-	return 0;
+static void update_msg_rx_state(struct drm_dp_mst_topology_mgr *mgr)
+{
+	mutex_lock(&mgr->lock);
+	if (mgr->reset_rx_state) {
+		mgr->reset_rx_state = false;
+		reset_msg_rx_state(&mgr->down_rep_recv);
+		reset_msg_rx_state(&mgr->up_req_recv);
+	}
+	mutex_unlock(&mgr->lock);
 }
 
 /**
@@ -4172,6 +4241,8 @@ int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u
 		*handled = true;
 	}
 
+	update_msg_rx_state(mgr);
+
 	if (esi[1] & DP_DOWN_REP_MSG_RDY) {
 		ret = drm_dp_mst_handle_down_rep(mgr);
 		*handled = true;
@@ -4680,61 +4751,6 @@ void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_
 }
 EXPORT_SYMBOL(drm_dp_mst_update_slots);
 
-static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
-				     int id, u8 start_slot, u8 num_slots)
-{
-	u8 payload_alloc[3], status;
-	int ret;
-	int retries = 0;
-
-	drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
-			   DP_PAYLOAD_TABLE_UPDATED);
-
-	payload_alloc[0] = id;
-	payload_alloc[1] = start_slot;
-	payload_alloc[2] = num_slots;
-
-	ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
-	if (ret != 3) {
-		drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
-		goto fail;
-	}
-
-retry:
-	ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
-	if (ret < 0) {
-		drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
-		goto fail;
-	}
-
-	if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
-		retries++;
-		if (retries < 20) {
-			usleep_range(10000, 20000);
-			goto retry;
-		}
-		drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
-			    status);
-		ret = -EINVAL;
-		goto fail;
-	}
-	ret = 0;
-fail:
-	return ret;
-}
-
-static int do_get_act_status(struct drm_dp_aux *aux)
-{
-	int ret;
-	u8 status;
-
-	ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
-	if (ret < 0)
-		return ret;
-
-	return status;
-}
-
 /**
  * drm_dp_check_act_status() - Polls for ACT handled status.
  * @mgr: manager to use
@@ -4752,28 +4768,9 @@ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
 	 * There doesn't seem to be any recommended retry count or timeout in
 	 * the MST specification. Since some hubs have been observed to take
 	 * over 1 second to update their payload allocations under certain
-	 * conditions, we use a rather large timeout value.
+	 * conditions, we use a rather large timeout value of 3 seconds.
 	 */
-	const int timeout_ms = 3000;
-	int ret, status;
-
-	ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
-				 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
-				 200, timeout_ms * USEC_PER_MSEC);
-	if (ret < 0 && status >= 0) {
-		drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
-			timeout_ms, status);
-		return -EINVAL;
-	} else if (status < 0) {
-		/*
-		 * Failure here isn't unexpected - the hub may have
-		 * just been unplugged
-		 */
-		drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
-		return status;
-	}
-
-	return 0;
+	return drm_dp_dpcd_poll_act_handled(mgr->aux, 3000);
 }
 EXPORT_SYMBOL(drm_dp_check_act_status);
 
@@ -4879,9 +4876,9 @@ static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
 	int i;
 
 	for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
-		if (drm_dp_dpcd_read(mgr->aux,
-				     DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
-				     &buf[i], 16) != 16)
+		if (drm_dp_dpcd_read_data(mgr->aux,
+					  DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
+					  &buf[i], 16) < 0)
 			return false;
 	}
 	return true;
@@ -4970,23 +4967,24 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 		}
 		seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
 
-		ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
-		if (ret != 2) {
+		ret = drm_dp_dpcd_read_data(mgr->aux, DP_FAUX_CAP, buf, 2);
+		if (ret < 0) {
 			seq_printf(m, "faux/mst read failed\n");
 			goto out;
 		}
 		seq_printf(m, "faux/mst: %*ph\n", 2, buf);
 
-		ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
-		if (ret != 1) {
+		ret = drm_dp_dpcd_read_data(mgr->aux, DP_MSTM_CTRL, buf, 1);
+		if (ret < 0) {
 			seq_printf(m, "mst ctrl read failed\n");
 			goto out;
 		}
 		seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
 
 		/* dump the standard OUI branch header */
-		ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
-		if (ret != DP_BRANCH_OUI_HEADER_SIZE) {
+		ret = drm_dp_dpcd_read_data(mgr->aux, DP_BRANCH_OUI, buf,
+					    DP_BRANCH_OUI_HEADER_SIZE);
+		if (ret < 0) {
 			seq_printf(m, "branch oui read failed\n");
 			goto out;
 		}
@@ -6110,14 +6108,14 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
 
 	/* DP-to-DP peer device */
 	if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
-		if (drm_dp_dpcd_read(&port->aux,
-				     DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+		if (drm_dp_dpcd_read_data(&port->aux,
+					  DP_DSC_SUPPORT, &endpoint_dsc, 1) < 0)
 			return NULL;
-		if (drm_dp_dpcd_read(&port->aux,
-				     DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+		if (drm_dp_dpcd_read_data(&port->aux,
+					  DP_FEC_CAPABILITY, &endpoint_fec, 1) < 0)
 			return NULL;
-		if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
-				     DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
+		if (drm_dp_dpcd_read_data(&immediate_upstream_port->aux,
+					  DP_DSC_SUPPORT, &upstream_dsc, 1) < 0)
 			return NULL;
 
 		/* Enpoint decompression with DP-to-DP peer device */
@@ -6155,8 +6153,8 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
 	if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) {
 		u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
 
-		if (drm_dp_dpcd_read(immediate_upstream_aux,
-				     DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
+		if (drm_dp_dpcd_read_data(immediate_upstream_aux,
+					  DP_DSC_SUPPORT, &upstream_dsc, 1) < 0)
 			return NULL;
 
 		if (!(upstream_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED))
@@ -6178,11 +6176,11 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
 	 * therefore the endpoint needs to be
 	 * both DSC and FEC capable.
 	 */
-	if (drm_dp_dpcd_read(&port->aux,
-	   DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
+	if (drm_dp_dpcd_read_data(&port->aux,
+				  DP_DSC_SUPPORT, &endpoint_dsc, 1) < 0)
 		return NULL;
-	if (drm_dp_dpcd_read(&port->aux,
-	   DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
+	if (drm_dp_dpcd_read_data(&port->aux,
+				  DP_FEC_CAPABILITY, &endpoint_fec, 1) < 0)
 		return NULL;
 	if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
 	   (endpoint_fec & DP_FEC_CAPABLE))