usb: typec: tcpm: Protocol Error handling

PD3.0 Spec 6.8.1 describes how to handle Protocol Error. There are
general rules defined in Table 6-61 which regulate incoming Message
handling. If the incoming Message is unexpected, unsupported, or
unrecognized, Protocol Error occurs. Follow the rules to handle these
situations. Also consider PD2.0 connection (PD2.0 Spec Table 6-36) for
backward compatibilities.

To know the types of AMS in all the recipient's states, identify those
AMS who are initiated by the port partner but not yet recorded in the
current code.

Besides, introduce a new state CHUNK_NOT_SUPP to delay the NOT_SUPPORTED
message after receiving a chunked message.

Tested-by: Hans de Goede <[e-mail]>
Reviewed-by: Heikki Krogerus <[e-mail]>
Signed-off-by: Kyle Tso <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/typec/tcpm/tcpm.c

···
 	S(PORT_RESET),				\
 	S(PORT_RESET_WAIT_OFF),			\
 						\
-	S(AMS_START)
+	S(AMS_START),				\
+	S(CHUNK_NOT_SUPP)
 
 #define FOREACH_AMS(S)				\
 	S(NONE_AMS),				\
···
 	/* Collision Avoidance and Atomic Message Sequence */
 	enum tcpm_state upcoming_state;
 	enum tcpm_ams ams;
+	enum tcpm_ams next_ams;
 	bool in_ams;
 
 #ifdef CONFIG_DEBUG_FS
···
 
 	tcpm_log(port, "AMS %s start", tcpm_ams_str[ams]);
 
-	if (!tcpm_ams_interruptible(port) && ams != HARD_RESET) {
+	if (!tcpm_ams_interruptible(port) &&
+	    !(ams == HARD_RESET || ams == SOFT_RESET_AMS)) {
 		port->upcoming_state = INVALID_STATE;
 		tcpm_log(port, "AMS %s not interruptible, aborting",
 			 tcpm_ams_str[port->ams]);
···
 			tcpm_set_state(port, HARD_RESET_START, 0);
 			return ret;
 		} else if (ams == SOFT_RESET_AMS) {
-			if (!port->explicit_contract) {
-				port->upcoming_state = INVALID_STATE;
+			if (!port->explicit_contract)
 				tcpm_set_cc(port, tcpm_rp_cc(port));
-				return ret;
-			}
+			tcpm_set_state(port, SOFT_RESET_SEND, 0);
+			return ret;
 		} else if (tcpm_vdm_ams(port)) {
 			/* tSinkTx is enforced in vdm_run_state_machine */
 			if (port->negotiated_rev >= PD_REV30)
···
 	case CMDT_INIT:
 		switch (cmd) {
 		case CMD_DISCOVER_IDENT:
+			if (PD_VDO_VID(p[0]) != USB_SID_PD)
+				break;
+
 			/* 6.4.4.3.1: Only respond as UFP (device) */
 			if (port->data_role == TYPEC_DEVICE &&
 			    port->nr_snk_vdo) {
···
 				return 0;
 			}
 			break;
+		case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
+			break;
 		default:
+			/* Unrecognized SVDM */
+			response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
+			rlen = 1;
 			break;
 		}
 		break;
 	case CMDT_RSP_NAK:
 		tcpm_ams_finish(port);
 		switch (cmd) {
+		case CMD_DISCOVER_IDENT:
+		case CMD_DISCOVER_SVID:
+		case CMD_DISCOVER_MODES:
+		case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
+			break;
 		case CMD_ENTER_MODE:
 			/* Back to USB Operation */
 			*adev_action = ADEV_NOTIFY_USB_AND_QUEUE_VDM;
 			return 0;
 		default:
+			/* Unrecognized SVDM */
+			response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
+			rlen = 1;
 			break;
 		}
 		break;
 	default:
+		response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
+		rlen = 1;
 		break;
 	}
 
···
 		port->vdm_state = VDM_STATE_DONE;
 	}
 
-	if (PD_VDO_SVDM(p[0]))
+	if (PD_VDO_SVDM(p[0])) {
 		rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action);
+	} else {
+		if (port->negotiated_rev >= PD_REV30)
+			tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
+	}
 
 	/*
 	 * We are done with any state stored in the port struct now, except
···
 	return ret;
 }
 
+static void tcpm_pd_handle_state(struct tcpm_port *port,
+				 enum tcpm_state state,
+				 enum tcpm_ams ams,
+				 unsigned int delay_ms)
+{
+	switch (port->state) {
+	case SRC_READY:
+	case SNK_READY:
+		port->ams = ams;
+		tcpm_set_state(port, state, delay_ms);
+		break;
+	/* 8.3.3.4.1.1 and 6.8.1 power transitioning */
+	case SNK_TRANSITION_SINK:
+	case SNK_TRANSITION_SINK_VBUS:
+	case SRC_TRANSITION_SUPPLY:
+		tcpm_set_state(port, HARD_RESET_SEND, 0);
+		break;
+	default:
+		if (!tcpm_ams_interruptible(port)) {
+			tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ?
+				       SRC_SOFT_RESET_WAIT_SNK_TX :
+				       SNK_SOFT_RESET,
+				       0);
+		} else {
+			/* process the Message 6.8.1 */
+			port->upcoming_state = state;
+			port->next_ams = ams;
+			tcpm_set_state(port, ready_state(port), delay_ms);
+		}
+		break;
+	}
+}
+
+static void tcpm_pd_handle_msg(struct tcpm_port *port,
+			       enum pd_msg_request message,
+			       enum tcpm_ams ams)
+{
+	switch (port->state) {
+	case SRC_READY:
+	case SNK_READY:
+		port->ams = ams;
+		tcpm_queue_message(port, message);
+		break;
+	/* PD 3.0 Spec 8.3.3.4.1.1 and 6.8.1 */
+	case SNK_TRANSITION_SINK:
+	case SNK_TRANSITION_SINK_VBUS:
+	case SRC_TRANSITION_SUPPLY:
+		tcpm_set_state(port, HARD_RESET_SEND, 0);
+		break;
+	default:
+		if (!tcpm_ams_interruptible(port)) {
+			tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ?
+				       SRC_SOFT_RESET_WAIT_SNK_TX :
+				       SNK_SOFT_RESET,
+				       0);
+		} else {
+			port->next_ams = ams;
+			tcpm_set_state(port, ready_state(port), 0);
+			/* 6.8.1 process the Message */
+			tcpm_queue_message(port, message);
+		}
+		break;
+	}
+}
+
 static void tcpm_pd_data_request(struct tcpm_port *port,
 				 const struct pd_message *msg)
 {
···
 
 	switch (type) {
 	case PD_DATA_SOURCE_CAP:
-		if (port->pwr_role != TYPEC_SINK)
-			break;
-
 		for (i = 0; i < cnt; i++)
 			port->source_caps[i] = le32_to_cpu(msg->payload[i]);
 
···
 		 * to comply with 6.2.1.1.5 of the USB PD 3.0 spec. We don't
 		 * support Rev 1.0 so just do nothing in that scenario.
 		 */
-		if (rev == PD_REV10)
+		if (rev == PD_REV10) {
+			if (port->ams == GET_SOURCE_CAPABILITIES)
+				tcpm_ams_finish(port);
 			break;
+		}
 
 		if (rev < PD_MAX_REV)
 			port->negotiated_rev = rev;
 
+		if (port->pwr_role == TYPEC_SOURCE) {
+			if (port->ams == GET_SOURCE_CAPABILITIES)
+				tcpm_pd_handle_state(port, SRC_READY, NONE_AMS, 0);
+			/* Unexpected Source Capabilities */
+			else
+				tcpm_pd_handle_msg(port,
+						   port->negotiated_rev < PD_REV30 ?
+						   PD_MSG_CTRL_REJECT :
+						   PD_MSG_CTRL_NOT_SUPP,
+						   NONE_AMS);
+		} else if (port->state == SNK_WAIT_CAPABILITIES) {
 		/*
 		 * This message may be received even if VBUS is not
 		 * present. This is quite unexpected; see USB PD
···
 		 * but be prepared to keep waiting for VBUS after it was
 		 * handled.
 		 */
-		tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
+			port->ams = POWER_NEGOTIATION;
+			tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
+		} else {
+			if (port->ams == GET_SOURCE_CAPABILITIES)
+				tcpm_ams_finish(port);
+			tcpm_pd_handle_state(port, SNK_NEGOTIATE_CAPABILITIES,
+					     POWER_NEGOTIATION, 0);
+		}
 		break;
 	case PD_DATA_REQUEST:
-		if (port->pwr_role != TYPEC_SOURCE ||
-		    cnt != 1) {
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
-			break;
-		}
-
 		/*
 		 * Adjust revision in subsequent message headers, as required,
 		 * to comply with 6.2.1.1.5 of the USB PD 3.0 spec. We don't
 		 * support Rev 1.0 so just reject in that scenario.
 		 */
 		if (rev == PD_REV10) {
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
+			tcpm_pd_handle_msg(port,
+					   port->negotiated_rev < PD_REV30 ?
+					   PD_MSG_CTRL_REJECT :
+					   PD_MSG_CTRL_NOT_SUPP,
+					   NONE_AMS);
 			break;
 		}
 
 		if (rev < PD_MAX_REV)
 			port->negotiated_rev = rev;
 
+		if (port->pwr_role != TYPEC_SOURCE || cnt != 1) {
+			tcpm_pd_handle_msg(port,
+					   port->negotiated_rev < PD_REV30 ?
+					   PD_MSG_CTRL_REJECT :
+					   PD_MSG_CTRL_NOT_SUPP,
+					   NONE_AMS);
+			break;
+		}
+
 		port->sink_request = le32_to_cpu(msg->payload[0]);
-		tcpm_set_state(port, SRC_NEGOTIATE_CAPABILITIES, 0);
+		if (port->state == SRC_SEND_CAPABILITIES)
+			tcpm_set_state(port, SRC_NEGOTIATE_CAPABILITIES, 0);
+		else
+			tcpm_pd_handle_state(port, SRC_NEGOTIATE_CAPABILITIES,
+					     POWER_NEGOTIATION, 0);
 		break;
 	case PD_DATA_SINK_CAP:
 		/* We don't do anything with this at the moment... */
···
 
 		port->nr_sink_caps = cnt;
 		port->sink_cap_done = true;
-		tcpm_set_state(port, SNK_READY, 0);
+		if (port->ams == GET_SINK_CAPABILITIES)
+			tcpm_pd_handle_state(port, ready_state(port), NONE_AMS, 0);
+		/* Unexpected Sink Capabilities */
+		else
+			tcpm_pd_handle_msg(port,
+					   port->negotiated_rev < PD_REV30 ?
+					   PD_MSG_CTRL_REJECT :
+					   PD_MSG_CTRL_NOT_SUPP,
+					   NONE_AMS);
 		break;
 	case PD_DATA_VENDOR_DEF:
 		tcpm_handle_vdm_request(port, msg->payload, cnt);
 		break;
 	case PD_DATA_BIST:
-		if (port->state == SRC_READY || port->state == SNK_READY) {
-			port->bist_request = le32_to_cpu(msg->payload[0]);
-			tcpm_set_state(port, BIST_RX, 0);
-		}
+		port->bist_request = le32_to_cpu(msg->payload[0]);
+		tcpm_pd_handle_state(port, BIST_RX, BIST, 0);
 		break;
 	case PD_DATA_ALERT:
 		tcpm_handle_alert(port, msg->payload, cnt);
···
 	case PD_DATA_BATT_STATUS:
 	case PD_DATA_GET_COUNTRY_INFO:
 		/* Currently unsupported */
-		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
+		tcpm_pd_handle_msg(port, port->negotiated_rev < PD_REV30 ?
+				   PD_MSG_CTRL_REJECT :
+				   PD_MSG_CTRL_NOT_SUPP,
+				   NONE_AMS);
 		break;
 	default:
-		tcpm_log(port, "Unhandled data message type %#x", type);
+		tcpm_pd_handle_msg(port, port->negotiated_rev < PD_REV30 ?
+				   PD_MSG_CTRL_REJECT :
+				   PD_MSG_CTRL_NOT_SUPP,
+				   NONE_AMS);
+		tcpm_log(port, "Unrecognized data message type %#x", type);
 		break;
 	}
 }
···
 	case PD_CTRL_PING:
 		break;
 	case PD_CTRL_GET_SOURCE_CAP:
-		switch (port->state) {
-		case SRC_READY:
-		case SNK_READY:
-			tcpm_queue_message(port, PD_MSG_DATA_SOURCE_CAP);
-			break;
-		default:
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
-			break;
-		}
+		tcpm_pd_handle_msg(port, PD_MSG_DATA_SOURCE_CAP, GET_SOURCE_CAPABILITIES);
 		break;
 	case PD_CTRL_GET_SINK_CAP:
-		switch (port->state) {
-		case SRC_READY:
-		case SNK_READY:
-			tcpm_queue_message(port, PD_MSG_DATA_SINK_CAP);
-			break;
-		default:
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
-			break;
-		}
+		tcpm_pd_handle_msg(port, PD_MSG_DATA_SINK_CAP, GET_SINK_CAPABILITIES);
 		break;
 	case PD_CTRL_GOTO_MIN:
 		break;
···
 			tcpm_set_state(port, FR_SWAP_SNK_SRC_NEW_SINK_READY, 0);
 			break;
 		default:
+			tcpm_pd_handle_state(port,
+					     port->pwr_role == TYPEC_SOURCE ?
+					     SRC_SOFT_RESET_WAIT_SNK_TX :
+					     SNK_SOFT_RESET,
+					     NONE_AMS, 0);
 			break;
 		}
 		break;
···
 			tcpm_set_state(port, ready_state(port), 0);
 			break;
 		default:
+			tcpm_pd_handle_state(port,
+					     port->pwr_role == TYPEC_SOURCE ?
+					     SRC_SOFT_RESET_WAIT_SNK_TX :
+					     SNK_SOFT_RESET,
+					     NONE_AMS, 0);
 			break;
 		}
 		break;
···
 			tcpm_set_state(port, SNK_TRANSITION_SINK, 0);
 			break;
 		case SOFT_RESET_SEND:
-			port->message_id = 0;
-			port->rx_msgid = -1;
 			if (port->ams == SOFT_RESET_AMS)
 				tcpm_ams_finish(port);
 			if (port->pwr_role == TYPEC_SOURCE) {
···
 			tcpm_set_state(port, FR_SWAP_SNK_SRC_TRANSITION_TO_OFF, 0);
 			break;
 		default:
+			tcpm_pd_handle_state(port,
+					     port->pwr_role == TYPEC_SOURCE ?
+					     SRC_SOFT_RESET_WAIT_SNK_TX :
+					     SNK_SOFT_RESET,
+					     NONE_AMS, 0);
 			break;
 		}
 		break;
 	case PD_CTRL_SOFT_RESET:
+		port->ams = SOFT_RESET_AMS;
 		tcpm_set_state(port, SOFT_RESET, 0);
 		break;
 	case PD_CTRL_DR_SWAP:
-		if (port->typec_caps.data != TYPEC_PORT_DRD) {
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
-			break;
-		}
 		/*
 		 * XXX
 		 * 6.3.9: If an alternate mode is active, a request to swap
 		 * alternate modes shall trigger a port reset.
 		 */
-		switch (port->state) {
-		case SRC_READY:
-		case SNK_READY:
-			tcpm_set_state(port, DR_SWAP_ACCEPT, 0);
-			break;
-		default:
-			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
-			break;
-		}
+		if (port->typec_caps.data != TYPEC_PORT_DRD)
+			tcpm_pd_handle_msg(port,
+					   port->negotiated_rev < PD_REV30 ?
+					   PD_MSG_CTRL_REJECT :
+					   PD_MSG_CTRL_NOT_SUPP,
+					   NONE_AMS);
+		else
+			tcpm_pd_handle_state(port, DR_SWAP_ACCEPT, DATA_ROLE_SWAP, 0);
 		break;
 	case PD_CTRL_PR_SWAP:
-		if (port->port_type != TYPEC_PORT_DRP) {
-			tcpm_queue_message(port, PD_MSG_CTRL_REJECT);
-			break;
-		}
-		switch (port->state) {
-		case SRC_READY:
-		case SNK_READY:
-			tcpm_set_state(port, PR_SWAP_ACCEPT, 0);
-			break;
-		default:
-			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
-			break;
-		}
+		if (port->port_type != TYPEC_PORT_DRP)
+			tcpm_pd_handle_msg(port,
+					   port->negotiated_rev < PD_REV30 ?
+					   PD_MSG_CTRL_REJECT :
+					   PD_MSG_CTRL_NOT_SUPP,
+					   NONE_AMS);
+		else
+			tcpm_pd_handle_state(port, PR_SWAP_ACCEPT, POWER_ROLE_SWAP, 0);
 		break;
 	case PD_CTRL_VCONN_SWAP:
-		switch (port->state) {
-		case SRC_READY:
-		case SNK_READY:
-			tcpm_set_state(port, VCONN_SWAP_ACCEPT, 0);
-			break;
-		default:
-			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
-			break;
-		}
+		tcpm_pd_handle_state(port, VCONN_SWAP_ACCEPT, VCONN_SWAP, 0);
 		break;
 	case PD_CTRL_GET_SOURCE_CAP_EXT:
 	case PD_CTRL_GET_STATUS:
···
 	case PD_CTRL_GET_PPS_STATUS:
 	case PD_CTRL_GET_COUNTRY_CODES:
 		/* Currently not supported */
-		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
+		tcpm_pd_handle_msg(port,
+				   port->negotiated_rev < PD_REV30 ?
+				   PD_MSG_CTRL_REJECT :
+				   PD_MSG_CTRL_NOT_SUPP,
+				   NONE_AMS);
 		break;
 	default:
-		tcpm_log(port, "Unhandled ctrl message type %#x", type);
+		tcpm_pd_handle_msg(port,
+				   port->negotiated_rev < PD_REV30 ?
+				   PD_MSG_CTRL_REJECT :
+				   PD_MSG_CTRL_NOT_SUPP,
+				   NONE_AMS);
+		tcpm_log(port, "Unrecognized ctrl message type %#x", type);
 		break;
 	}
 }
···
 	unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);
 
 	if (!(msg->ext_msg.header & PD_EXT_HDR_CHUNKED)) {
+		tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		tcpm_log(port, "Unchunked extended messages unsupported");
 		return;
 	}
 
 	if (data_size > PD_EXT_MAX_CHUNK_DATA) {
+		tcpm_pd_handle_state(port, CHUNK_NOT_SUPP, NONE_AMS, PD_T_CHUNK_NOT_SUPP);
 		tcpm_log(port, "Chunk handling not yet supported");
 		return;
 	}
···
 		 */
 		if (msg->ext_msg.data[USB_PD_EXT_SDB_EVENT_FLAGS] &
 		    USB_PD_EXT_SDB_PPS_EVENTS)
-			tcpm_set_state(port, GET_PPS_STATUS_SEND, 0);
+			tcpm_pd_handle_state(port, GET_PPS_STATUS_SEND,
+					     GETTING_SOURCE_SINK_STATUS, 0);
+
 		else
-			tcpm_set_state(port, ready_state(port), 0);
+			tcpm_pd_handle_state(port, ready_state(port), NONE_AMS, 0);
 		break;
 	case PD_EXT_PPS_STATUS:
 		/*
 		 * For now the PPS status message is used to clear events
 		 * and nothing more.
 		 */
-		tcpm_set_state(port, ready_state(port), 0);
+		tcpm_pd_handle_state(port, ready_state(port), NONE_AMS, 0);
 		break;
 	case PD_EXT_SOURCE_CAP_EXT:
 	case PD_EXT_GET_BATT_CAP:
···
 	case PD_EXT_FW_UPDATE_RESPONSE:
 	case PD_EXT_COUNTRY_INFO:
 	case PD_EXT_COUNTRY_CODES:
-		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
+		tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
 		break;
 	default:
-		tcpm_log(port, "Unhandled extended message type %#x", type);
+		tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
+		tcpm_log(port, "Unrecognized extended message type %#x", type);
 		break;
 	}
 }
···
 			tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP);
 			break;
 		case PD_MSG_DATA_SINK_CAP:
-			tcpm_pd_send_sink_caps(port);
+			ret = tcpm_pd_send_sink_caps(port);
+			if (ret < 0) {
+				tcpm_log(port, "Unable to send snk caps, ret=%d", ret);
+				tcpm_set_state(port, SNK_SOFT_RESET, 0);
+			}
+			tcpm_ams_finish(port);
 			break;
 		case PD_MSG_DATA_SOURCE_CAP:
 			ret = tcpm_pd_send_source_caps(port);
···
 					 ret);
 				tcpm_set_state(port, SOFT_RESET_SEND, 0);
 			} else if (port->pwr_role == TYPEC_SOURCE) {
+				tcpm_ams_finish(port);
 				tcpm_set_state(port, HARD_RESET_SEND,
 					       PD_T_SENDER_RESPONSE);
+			} else {
+				tcpm_ams_finish(port);
 			}
 			break;
 		default:
···
 
 		if (port->ams != NONE_AMS)
 			tcpm_ams_finish(port);
+		if (port->next_ams != NONE_AMS) {
+			port->ams = port->next_ams;
+			port->next_ams = NONE_AMS;
+		}
+
 		/*
 		 * If previous AMS is interrupted, switch to the upcoming
 		 * state.
···
 
 		if (port->ams != NONE_AMS)
 			tcpm_ams_finish(port);
+		if (port->next_ams != NONE_AMS) {
+			port->ams = port->next_ams;
+			port->next_ams = NONE_AMS;
+		}
+
 		/*
 		 * If previous AMS is interrupted, switch to the upcoming
 		 * state.
···
 		port->message_id = 0;
 		port->rx_msgid = -1;
 		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
+		tcpm_ams_finish(port);
 		if (port->pwr_role == TYPEC_SOURCE) {
 			port->upcoming_state = SRC_SEND_CAPABILITIES;
 			tcpm_ams_start(port, POWER_NEGOTIATION);
···
 		break;
 	case DR_SWAP_SEND_TIMEOUT:
 		tcpm_swap_complete(port, -ETIMEDOUT);
+		tcpm_ams_finish(port);
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 	case DR_SWAP_CHANGE_DR:
···
 				       TYPEC_HOST);
 			port->send_discover = true;
 		}
+		tcpm_ams_finish(port);
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 
···
 
 	case VCONN_SWAP_ACCEPT:
 		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
+		tcpm_ams_finish(port);
 		tcpm_set_state(port, VCONN_SWAP_START, 0);
 		break;
 	case VCONN_SWAP_SEND:
···
 		upcoming_state = port->upcoming_state;
 		port->upcoming_state = INVALID_STATE;
 		tcpm_set_state(port, upcoming_state, 0);
+		break;
+
+	/* Chunk state */
+	case CHUNK_NOT_SUPP:
+		tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP);
+		tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ? SRC_READY : SNK_READY, 0);
 		break;
 	default:
 		WARN(1, "Unexpected port state %d\n", port->state);
···
 
 	if (port->ams != NONE_AMS)
 		port->ams = NONE_AMS;
+	if (port->hard_reset_count < PD_N_HARD_RESET_COUNT)
+		port->ams = HARD_RESET;
 	/*
 	 * If we keep receiving hard reset requests, executing the hard reset
 	 * must have failed. Revert to error recovery if that happens.

include/linux/usb/pd.h

···
 #define PD_T_SWAP_SRC_START	20	/* Minimum of 20ms */
 #define PD_T_BIST_CONT_MODE	50	/* 30 - 60 ms */
 #define PD_T_SINK_TX		16	/* 16 - 20 ms */
+#define PD_T_CHUNK_NOT_SUPP	42	/* 40 - 50 ms */
 
 #define PD_T_DRP_TRY		100	/* 75 - 150 ms */
 #define PD_T_DRP_TRYWAIT	600	/* 400 - 800 ms */