[PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Kyle Tso]

v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com

"usb: typec: tcpm: AMS and Collision Avoidance"
 - removed the signed-off
 - modified the coding style suggested from Heikki
 - added FR_SWAP AMS handling

"usb: typec: tcpm: Protocol Error handling"
 - removed the signed-off
 - modified the coding style suggested from Heikki
 - modified more coding style problems (line wrapping limit)

"usb: typec: tcpm: Respond Wait if VDM state machine is running"
 - no change

-------------------------------------------------------------------

Kyle Tso (3):
  usb: typec: tcpm: AMS and Collision Avoidance
  usb: typec: tcpm: Protocol Error handling
  usb: typec: tcpm: Respond Wait if VDM state machine is running

 drivers/usb/typec/tcpm/tcpm.c | 1001 +++++++++++++++++++++++++++------
 include/linux/usb/pd.h        |    2 +
 include/linux/usb/tcpm.h      |    4 +
 3 files changed, 829 insertions(+), 178 deletions(-)

-- 
2.30.0.284.gd98b1dd5eaa7-goog

[PATCH v6 1/3] usb: typec: tcpm: AMS and Collision Avoidance

[Kyle Tso]

This patch provides the implementation of Collision Avoidance introduced
in PD3.0. The start of each Atomic Message Sequence (AMS) initiated by
the port will be denied if the current AMS is not interruptible. The
Source port will set the CC to SinkTxNG if it is going to initiate an
AMS, and SinkTxOk otherwise. Meanwhile, any AMS initiated by a Sink port
will be denied in TCPM if the port partner (Source) sets SinkTxNG except
for HARD_RESET and SOFT_RESET.

Signed-off-by: Kyle Tso <kyletso@google.com>
---
Changelog since v5:
 - removed the signed-off                                                       
 - modified the coding style suggested from Heikki                              
 - added FR_SWAP AMS handling

 drivers/usb/typec/tcpm/tcpm.c | 620 ++++++++++++++++++++++++++++------
 include/linux/usb/pd.h        |   1 +
 include/linux/usb/tcpm.h      |   4 +
 3 files changed, 527 insertions(+), 98 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 22a85b396f69..2b16d2764092 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -76,6 +76,8 @@
 	S(SNK_HARD_RESET_SINK_ON),		\
 						\
 	S(SOFT_RESET),				\
+	S(SRC_SOFT_RESET_WAIT_SNK_TX),		\
+	S(SNK_SOFT_RESET),			\
 	S(SOFT_RESET_SEND),			\
 						\
 	S(DR_SWAP_ACCEPT),			\
@@ -139,7 +141,45 @@
 						\
 	S(ERROR_RECOVERY),			\
 	S(PORT_RESET),				\
-	S(PORT_RESET_WAIT_OFF)
+	S(PORT_RESET_WAIT_OFF),			\
+						\
+	S(AMS_START)
+
+#define FOREACH_AMS(S)				\
+	S(NONE_AMS),				\
+	S(POWER_NEGOTIATION),			\
+	S(GOTOMIN),				\
+	S(SOFT_RESET_AMS),			\
+	S(HARD_RESET),				\
+	S(CABLE_RESET),				\
+	S(GET_SOURCE_CAPABILITIES),		\
+	S(GET_SINK_CAPABILITIES),		\
+	S(POWER_ROLE_SWAP),			\
+	S(FAST_ROLE_SWAP),			\
+	S(DATA_ROLE_SWAP),			\
+	S(VCONN_SWAP),				\
+	S(SOURCE_ALERT),			\
+	S(GETTING_SOURCE_EXTENDED_CAPABILITIES),\
+	S(GETTING_SOURCE_SINK_STATUS),		\
+	S(GETTING_BATTERY_CAPABILITIES),	\
+	S(GETTING_BATTERY_STATUS),		\
+	S(GETTING_MANUFACTURER_INFORMATION),	\
+	S(SECURITY),				\
+	S(FIRMWARE_UPDATE),			\
+	S(DISCOVER_IDENTITY),			\
+	S(SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY),	\
+	S(DISCOVER_SVIDS),			\
+	S(DISCOVER_MODES),			\
+	S(DFP_TO_UFP_ENTER_MODE),		\
+	S(DFP_TO_UFP_EXIT_MODE),		\
+	S(DFP_TO_CABLE_PLUG_ENTER_MODE),	\
+	S(DFP_TO_CABLE_PLUG_EXIT_MODE),		\
+	S(ATTENTION),				\
+	S(BIST),				\
+	S(UNSTRUCTURED_VDMS),			\
+	S(STRUCTURED_VDMS),			\
+	S(COUNTRY_INFO),			\
+	S(COUNTRY_CODES)
 
 #define GENERATE_ENUM(e)	e
 #define GENERATE_STRING(s)	#s
@@ -152,6 +192,14 @@ static const char * const tcpm_states[] = {
 	FOREACH_STATE(GENERATE_STRING)
 };
 
+enum tcpm_ams {
+	FOREACH_AMS(GENERATE_ENUM)
+};
+
+static const char * const tcpm_ams_str[] = {
+	FOREACH_AMS(GENERATE_STRING)
+};
+
 enum vdm_states {
 	VDM_STATE_ERR_BUSY = -3,
 	VDM_STATE_ERR_SEND = -2,
@@ -161,6 +209,7 @@ enum vdm_states {
 	VDM_STATE_READY = 1,
 	VDM_STATE_BUSY = 2,
 	VDM_STATE_WAIT_RSP_BUSY = 3,
+	VDM_STATE_SEND_MESSAGE = 4,
 };
 
 enum pd_msg_request {
@@ -381,6 +430,11 @@ struct tcpm_port {
 	/* Sink caps have been queried */
 	bool sink_cap_done;
 
+	/* Collision Avoidance and Atomic Message Sequence */
+	enum tcpm_state upcoming_state;
+	enum tcpm_ams ams;
+	bool in_ams;
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
 	struct mutex logbuffer_lock;	/* log buffer access lock */
@@ -396,6 +450,12 @@ struct pd_rx_event {
 	struct pd_message msg;
 };
 
+static const char * const pd_rev[] = {
+	[PD_REV10]		= "rev1",
+	[PD_REV20]		= "rev2",
+	[PD_REV30]		= "rev3",
+};
+
 #define tcpm_cc_is_sink(cc) \
 	((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
 	 (cc) == TYPEC_CC_RP_3_0)
@@ -440,6 +500,10 @@ struct pd_rx_event {
 	((port)->typec_caps.data == TYPEC_PORT_DFP ? \
 	TYPEC_HOST : TYPEC_DEVICE)
 
+#define tcpm_sink_tx_ok(port) \
+	(tcpm_port_is_sink(port) && \
+	((port)->cc1 == TYPEC_CC_RP_3_0 || (port)->cc2 == TYPEC_CC_RP_3_0))
+
 static enum tcpm_state tcpm_default_state(struct tcpm_port *port)
 {
 	if (port->port_type == TYPEC_PORT_DRP) {
@@ -666,6 +730,67 @@ static void tcpm_debugfs_exit(const struct tcpm_port *port) { }
 
 #endif
 
+static void tcpm_set_cc(struct tcpm_port *port, enum typec_cc_status cc)
+{
+	tcpm_log(port, "cc:=%d", cc);
+	port->cc_req = cc;
+	port->tcpc->set_cc(port->tcpc, cc);
+}
+
+/*
+ * Determine RP value to set based on maximum current supported
+ * by a port if configured as source.
+ * Returns CC value to report to link partner.
+ */
+static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
+{
+	const u32 *src_pdo = port->src_pdo;
+	int nr_pdo = port->nr_src_pdo;
+	int i;
+
+	/*
+	 * Search for first entry with matching voltage.
+	 * It should report the maximum supported current.
+	 */
+	for (i = 0; i < nr_pdo; i++) {
+		const u32 pdo = src_pdo[i];
+
+		if (pdo_type(pdo) == PDO_TYPE_FIXED &&
+		    pdo_fixed_voltage(pdo) == 5000) {
+			unsigned int curr = pdo_max_current(pdo);
+
+			if (curr >= 3000)
+				return TYPEC_CC_RP_3_0;
+			else if (curr >= 1500)
+				return TYPEC_CC_RP_1_5;
+			return TYPEC_CC_RP_DEF;
+		}
+	}
+
+	return TYPEC_CC_RP_DEF;
+}
+
+static int tcpm_ams_finish(struct tcpm_port *port)
+{
+	int ret = 0;
+
+	tcpm_log(port, "AMS %s finished", tcpm_ams_str[port->ams]);
+
+	if (port->pd_capable && port->pwr_role == TYPEC_SOURCE) {
+		if (port->negotiated_rev >= PD_REV30)
+			tcpm_set_cc(port, SINK_TX_OK);
+		else
+			tcpm_set_cc(port, SINK_TX_NG);
+	} else if (port->pwr_role == TYPEC_SOURCE) {
+		tcpm_set_cc(port, tcpm_rp_cc(port));
+	}
+
+	port->in_ams = false;
+	port->ams = NONE_AMS;
+
+	return ret;
+}
+
 static int tcpm_pd_transmit(struct tcpm_port *port,
 			    enum tcpm_transmit_type type,
 			    const struct pd_message *msg)
@@ -693,13 +818,30 @@ static int tcpm_pd_transmit(struct tcpm_port *port,
 	switch (port->tx_status) {
 	case TCPC_TX_SUCCESS:
 		port->message_id = (port->message_id + 1) & PD_HEADER_ID_MASK;
-		return 0;
+		/*
+		 * USB PD rev 2.0, 8.3.2.2.1:
+		 * USB PD rev 3.0, 8.3.2.1.3:
+		 * "... Note that every AMS is Interruptible until the first
+		 * Message in the sequence has been successfully sent (GoodCRC
+		 * Message received)."
+		 */
+		if (port->ams != NONE_AMS)
+			port->in_ams = true;
+		break;
 	case TCPC_TX_DISCARDED:
-		return -EAGAIN;
+		ret = -EAGAIN;
+		break;
 	case TCPC_TX_FAILED:
 	default:
-		return -EIO;
+		ret = -EIO;
+		break;
 	}
+
+	/* Some AMS don't expect responses. Finish them here. */
+	if (port->ams == ATTENTION || port->ams == SOURCE_ALERT)
+		tcpm_ams_finish(port);
+
+	return ret;
 }
 
 void tcpm_pd_transmit_complete(struct tcpm_port *port,
@@ -804,39 +946,6 @@ static int tcpm_set_current_limit(struct tcpm_port *port, u32 max_ma, u32 mv)
 	return ret;
 }
 
-/*
- * Determine RP value to set based on maximum current supported
- * by a port if configured as source.
- * Returns CC value to report to link partner.
- */
-static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
-{
-	const u32 *src_pdo = port->src_pdo;
-	int nr_pdo = port->nr_src_pdo;
-	int i;
-
-	/*
-	 * Search for first entry with matching voltage.
-	 * It should report the maximum supported current.
-	 */
-	for (i = 0; i < nr_pdo; i++) {
-		const u32 pdo = src_pdo[i];
-
-		if (pdo_type(pdo) == PDO_TYPE_FIXED &&
-		    pdo_fixed_voltage(pdo) == 5000) {
-			unsigned int curr = pdo_max_current(pdo);
-
-			if (curr >= 3000)
-				return TYPEC_CC_RP_3_0;
-			else if (curr >= 1500)
-				return TYPEC_CC_RP_1_5;
-			return TYPEC_CC_RP_DEF;
-		}
-	}
-
-	return TYPEC_CC_RP_DEF;
-}
-
 static int tcpm_set_attached_state(struct tcpm_port *port, bool attached)
 {
 	return port->tcpc->set_roles(port->tcpc, attached, port->pwr_role,
@@ -1000,16 +1109,17 @@ static void tcpm_set_state(struct tcpm_port *port, enum tcpm_state state,
 			   unsigned int delay_ms)
 {
 	if (delay_ms) {
-		tcpm_log(port, "pending state change %s -> %s @ %u ms",
-			 tcpm_states[port->state], tcpm_states[state],
-			 delay_ms);
+		tcpm_log(port, "pending state change %s -> %s @ %u ms [%s %s]",
+			 tcpm_states[port->state], tcpm_states[state], delay_ms,
+			 pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
 		port->delayed_state = state;
 		mod_tcpm_delayed_work(port, delay_ms);
 		port->delayed_runtime = ktime_add(ktime_get(), ms_to_ktime(delay_ms));
 		port->delay_ms = delay_ms;
 	} else {
-		tcpm_log(port, "state change %s -> %s",
-			 tcpm_states[port->state], tcpm_states[state]);
+		tcpm_log(port, "state change %s -> %s [%s %s]",
+			 tcpm_states[port->state], tcpm_states[state],
+			 pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
 		port->delayed_state = INVALID_STATE;
 		port->prev_state = port->state;
 		port->state = state;
@@ -1031,10 +1141,11 @@ static void tcpm_set_state_cond(struct tcpm_port *port, enum tcpm_state state,
 		tcpm_set_state(port, state, delay_ms);
 	else
 		tcpm_log(port,
-			 "skipped %sstate change %s -> %s [%u ms], context state %s",
+			 "skipped %sstate change %s -> %s [%u ms], context state %s [%s %s]",
 			 delay_ms ? "delayed " : "",
 			 tcpm_states[port->state], tcpm_states[state],
-			 delay_ms, tcpm_states[port->enter_state]);
+			 delay_ms, tcpm_states[port->enter_state],
+			 pd_rev[port->negotiated_rev], tcpm_ams_str[port->ams]);
 }
 
 static void tcpm_queue_message(struct tcpm_port *port,
@@ -1044,6 +1155,149 @@ static void tcpm_queue_message(struct tcpm_port *port,
 	mod_tcpm_delayed_work(port, 0);
 }
 
+static bool tcpm_vdm_ams(struct tcpm_port *port)
+{
+	switch (port->ams) {
+	case DISCOVER_IDENTITY:
+	case SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY:
+	case DISCOVER_SVIDS:
+	case DISCOVER_MODES:
+	case DFP_TO_UFP_ENTER_MODE:
+	case DFP_TO_UFP_EXIT_MODE:
+	case DFP_TO_CABLE_PLUG_ENTER_MODE:
+	case DFP_TO_CABLE_PLUG_EXIT_MODE:
+	case ATTENTION:
+	case UNSTRUCTURED_VDMS:
+	case STRUCTURED_VDMS:
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+static bool tcpm_ams_interruptible(struct tcpm_port *port)
+{
+	switch (port->ams) {
+	/* Interruptible AMS */
+	case NONE_AMS:
+	case SECURITY:
+	case FIRMWARE_UPDATE:
+	case DISCOVER_IDENTITY:
+	case SOURCE_STARTUP_CABLE_PLUG_DISCOVER_IDENTITY:
+	case DISCOVER_SVIDS:
+	case DISCOVER_MODES:
+	case DFP_TO_UFP_ENTER_MODE:
+	case DFP_TO_UFP_EXIT_MODE:
+	case DFP_TO_CABLE_PLUG_ENTER_MODE:
+	case DFP_TO_CABLE_PLUG_EXIT_MODE:
+	case UNSTRUCTURED_VDMS:
+	case STRUCTURED_VDMS:
+	case COUNTRY_INFO:
+	case COUNTRY_CODES:
+		break;
+	/* Non-Interruptible AMS */
+	default:
+		if (port->in_ams)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+static int tcpm_ams_start(struct tcpm_port *port, enum tcpm_ams ams)
+{
+	int ret = 0;
+
+	tcpm_log(port, "AMS %s start", tcpm_ams_str[ams]);
+
+	if (!tcpm_ams_interruptible(port) && ams != HARD_RESET) {
+		port->upcoming_state = INVALID_STATE;
+		tcpm_log(port, "AMS %s not interruptible, aborting",
+			 tcpm_ams_str[port->ams]);
+		return -EAGAIN;
+	}
+
+	if (port->pwr_role == TYPEC_SOURCE) {
+		enum typec_cc_status cc_req = port->cc_req;
+
+		port->ams = ams;
+
+		if (ams == HARD_RESET) {
+			tcpm_set_cc(port, tcpm_rp_cc(port));
+			tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
+			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;
+				tcpm_set_cc(port, tcpm_rp_cc(port));
+				return ret;
+			}
+		} else if (tcpm_vdm_ams(port)) {
+			/* tSinkTx is enforced in vdm_run_state_machine */
+			if (port->negotiated_rev >= PD_REV30)
+				tcpm_set_cc(port, SINK_TX_NG);
+			return ret;
+		}
+
+		if (port->negotiated_rev >= PD_REV30)
+			tcpm_set_cc(port, SINK_TX_NG);
+
+		switch (port->state) {
+		case SRC_READY:
+		case SRC_STARTUP:
+		case SRC_SOFT_RESET_WAIT_SNK_TX:
+		case SOFT_RESET:
+		case SOFT_RESET_SEND:
+			if (port->negotiated_rev >= PD_REV30)
+				tcpm_set_state(port, AMS_START,
+					       cc_req == SINK_TX_OK ?
+					       PD_T_SINK_TX : 0);
+			else
+				tcpm_set_state(port, AMS_START, 0);
+			break;
+		default:
+			if (port->negotiated_rev >= PD_REV30)
+				tcpm_set_state(port, SRC_READY,
+					       cc_req == SINK_TX_OK ?
+					       PD_T_SINK_TX : 0);
+			else
+				tcpm_set_state(port, SRC_READY, 0);
+			break;
+		}
+	} else {
+		if (port->negotiated_rev >= PD_REV30 &&
+		    !tcpm_sink_tx_ok(port) &&
+		    ams != SOFT_RESET_AMS &&
+		    ams != HARD_RESET) {
+			port->upcoming_state = INVALID_STATE;
+			tcpm_log(port, "Sink TX No Go");
+			return -EAGAIN;
+		}
+
+		port->ams = ams;
+
+		if (ams == HARD_RESET) {
+			tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
+			tcpm_set_state(port, HARD_RESET_START, 0);
+			return ret;
+		} else if (tcpm_vdm_ams(port)) {
+			return ret;
+		}
+
+		if (port->state == SNK_READY ||
+		    port->state == SNK_SOFT_RESET)
+			tcpm_set_state(port, AMS_START, 0);
+		else
+			tcpm_set_state(port, SNK_READY, 0);
+	}
+
+	return ret;
+}
+
 /*
  * VDM/VDO handling functions
  */
@@ -1236,6 +1490,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 		if (IS_ERR_OR_NULL(port->partner))
 			break;
 
+		tcpm_ams_finish(port);
+
 		switch (cmd) {
 		case CMD_DISCOVER_IDENT:
 			/* 6.4.4.3.1 */
@@ -1286,6 +1542,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 		}
 		break;
 	case CMDT_RSP_NAK:
+		tcpm_ams_finish(port);
 		switch (cmd) {
 		case CMD_ENTER_MODE:
 			/* Back to USB Operation */
@@ -1435,7 +1692,8 @@ static unsigned int vdm_ready_timeout(u32 vdm_hdr)
 static void vdm_run_state_machine(struct tcpm_port *port)
 {
 	struct pd_message msg;
-	int i, res;
+	int i, res = 0;
+	u32 vdo_hdr = port->vdo_data[0];
 
 	switch (port->vdm_state) {
 	case VDM_STATE_READY:
@@ -1452,26 +1710,45 @@ static void vdm_run_state_machine(struct tcpm_port *port)
 		if (port->state != SRC_READY && port->state != SNK_READY)
 			break;
 
-		/* Prepare and send VDM */
-		memset(&msg, 0, sizeof(msg));
-		msg.header = PD_HEADER_LE(PD_DATA_VENDOR_DEF,
-					  port->pwr_role,
-					  port->data_role,
-					  port->negotiated_rev,
-					  port->message_id, port->vdo_count);
-		for (i = 0; i < port->vdo_count; i++)
-			msg.payload[i] = cpu_to_le32(port->vdo_data[i]);
-		res = tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
-		if (res < 0) {
-			port->vdm_state = VDM_STATE_ERR_SEND;
-		} else {
-			unsigned long timeout;
+		/* TODO: AMS operation for Unstructured VDM */
+		if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMDT(vdo_hdr) == CMDT_INIT) {
+			switch (PD_VDO_CMD(vdo_hdr)) {
+			case CMD_DISCOVER_IDENT:
+				res = tcpm_ams_start(port, DISCOVER_IDENTITY);
+				break;
+			case CMD_DISCOVER_SVID:
+				res = tcpm_ams_start(port, DISCOVER_SVIDS);
+				break;
+			case CMD_DISCOVER_MODES:
+				res = tcpm_ams_start(port, DISCOVER_MODES);
+				break;
+			case CMD_ENTER_MODE:
+				res = tcpm_ams_start(port, DFP_TO_UFP_ENTER_MODE);
+				break;
+			case CMD_EXIT_MODE:
+				res = tcpm_ams_start(port, DFP_TO_UFP_EXIT_MODE);
+				break;
+			case CMD_ATTENTION:
+				res = tcpm_ams_start(port, ATTENTION);
+				break;
+			case VDO_CMD_VENDOR(0) ... VDO_CMD_VENDOR(15):
+				res = tcpm_ams_start(port, STRUCTURED_VDMS);
+				break;
+			default:
+				res = -EOPNOTSUPP;
+				break;
+			}
 
-			port->vdm_retries = 0;
-			port->vdm_state = VDM_STATE_BUSY;
-			timeout = vdm_ready_timeout(port->vdo_data[0]);
-			mod_vdm_delayed_work(port, timeout);
+			if (res < 0)
+				return;
 		}
+
+		port->vdm_state = VDM_STATE_SEND_MESSAGE;
+		mod_vdm_delayed_work(port, (port->negotiated_rev >= PD_REV30 &&
+					    port->pwr_role == TYPEC_SOURCE &&
+					    PD_VDO_SVDM(vdo_hdr) &&
+					    PD_VDO_CMDT(vdo_hdr) == CMDT_INIT) ?
+					   PD_T_SINK_TX : 0);
 		break;
 	case VDM_STATE_WAIT_RSP_BUSY:
 		port->vdo_data[0] = port->vdo_retry;
@@ -1480,6 +1757,8 @@ static void vdm_run_state_machine(struct tcpm_port *port)
 		break;
 	case VDM_STATE_BUSY:
 		port->vdm_state = VDM_STATE_ERR_TMOUT;
+		if (port->ams != NONE_AMS)
+			tcpm_ams_finish(port);
 		break;
 	case VDM_STATE_ERR_SEND:
 		/*
@@ -1492,6 +1771,29 @@ static void vdm_run_state_machine(struct tcpm_port *port)
 			tcpm_log(port, "VDM Tx error, retry");
 			port->vdm_retries++;
 			port->vdm_state = VDM_STATE_READY;
+			tcpm_ams_finish(port);
+		}
+		break;
+	case VDM_STATE_SEND_MESSAGE:
+		/* Prepare and send VDM */
+		memset(&msg, 0, sizeof(msg));
+		msg.header = PD_HEADER_LE(PD_DATA_VENDOR_DEF,
+					  port->pwr_role,
+					  port->data_role,
+					  port->negotiated_rev,
+					  port->message_id, port->vdo_count);
+		for (i = 0; i < port->vdo_count; i++)
+			msg.payload[i] = cpu_to_le32(port->vdo_data[i]);
+		res = tcpm_pd_transmit(port, TCPC_TX_SOP, &msg);
+		if (res < 0) {
+			port->vdm_state = VDM_STATE_ERR_SEND;
+		} else {
+			unsigned long timeout;
+
+			port->vdm_retries = 0;
+			port->vdm_state = VDM_STATE_BUSY;
+			timeout = vdm_ready_timeout(vdo_hdr);
+			mod_vdm_delayed_work(port, timeout);
 		}
 		break;
 	default:
@@ -1514,7 +1816,8 @@ static void vdm_state_machine_work(struct kthread_work *work)
 		prev_state = port->vdm_state;
 		vdm_run_state_machine(port);
 	} while (port->vdm_state != prev_state &&
-		 port->vdm_state != VDM_STATE_BUSY);
+		 port->vdm_state != VDM_STATE_BUSY &&
+		 port->vdm_state != VDM_STATE_SEND_MESSAGE);
 
 	mutex_unlock(&port->lock);
 }
@@ -1997,11 +2300,14 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 		case SOFT_RESET_SEND:
 			port->message_id = 0;
 			port->rx_msgid = -1;
-			if (port->pwr_role == TYPEC_SOURCE)
-				next_state = SRC_SEND_CAPABILITIES;
-			else
-				next_state = SNK_WAIT_CAPABILITIES;
-			tcpm_set_state(port, next_state, 0);
+			if (port->ams == SOFT_RESET_AMS)
+				tcpm_ams_finish(port);
+			if (port->pwr_role == TYPEC_SOURCE) {
+				port->upcoming_state = SRC_SEND_CAPABILITIES;
+				tcpm_ams_start(port, POWER_NEGOTIATION);
+			} else {
+				tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
+			}
 			break;
 		case DR_SWAP_SEND:
 			tcpm_set_state(port, DR_SWAP_CHANGE_DR, 0);
@@ -2776,13 +3082,6 @@ static bool tcpm_start_toggling(struct tcpm_port *port, enum typec_cc_status cc)
 	return ret == 0;
 }
 
-static void tcpm_set_cc(struct tcpm_port *port, enum typec_cc_status cc)
-{
-	tcpm_log(port, "cc:=%d", cc);
-	port->cc_req = cc;
-	port->tcpc->set_cc(port->tcpc, cc);
-}
-
 static int tcpm_init_vbus(struct tcpm_port *port)
 {
 	int ret;
@@ -2912,6 +3211,8 @@ static void tcpm_reset_port(struct tcpm_port *port)
 		ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, false);
 		tcpm_log_force(port, "Disable vbus discharge ret:%d", ret);
 	}
+	port->in_ams = false;
+	port->ams = NONE_AMS;
 	tcpm_unregister_altmodes(port);
 	tcpm_typec_disconnect(port);
 	port->attached = false;
@@ -3090,6 +3391,7 @@ static void run_state_machine(struct tcpm_port *port)
 	int ret;
 	enum typec_pwr_opmode opmode;
 	unsigned int msecs;
+	enum tcpm_state upcoming_state;
 
 	port->enter_state = port->state;
 	switch (port->state) {
@@ -3190,7 +3492,12 @@ static void run_state_machine(struct tcpm_port *port)
 		port->message_id = 0;
 		port->rx_msgid = -1;
 		port->explicit_contract = false;
-		tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
+		/* SNK -> SRC POWER/FAST_ROLE_SWAP finished */
+		if (port->ams == POWER_ROLE_SWAP ||
+		    port->ams == FAST_ROLE_SWAP)
+			tcpm_ams_finish(port);
+		port->upcoming_state = SRC_SEND_CAPABILITIES;
+		tcpm_ams_start(port, POWER_NEGOTIATION);
 		break;
 	case SRC_SEND_CAPABILITIES:
 		port->caps_count++;
@@ -3272,6 +3579,19 @@ static void run_state_machine(struct tcpm_port *port)
 		tcpm_swap_complete(port, 0);
 		tcpm_typec_connect(port);
 
+		if (port->ams != NONE_AMS)
+			tcpm_ams_finish(port);
+		/*
+		 * If previous AMS is interrupted, switch to the upcoming
+		 * state.
+		 */
+		if (port->upcoming_state != INVALID_STATE) {
+			upcoming_state = port->upcoming_state;
+			port->upcoming_state = INVALID_STATE;
+			tcpm_set_state(port, upcoming_state, 0);
+			break;
+		}
+
 		tcpm_check_send_discover(port);
 		/*
 		 * 6.3.5
@@ -3389,6 +3709,12 @@ static void run_state_machine(struct tcpm_port *port)
 		port->message_id = 0;
 		port->rx_msgid = -1;
 		port->explicit_contract = false;
+
+		if (port->ams == POWER_ROLE_SWAP ||
+		    port->ams == FAST_ROLE_SWAP)
+			/* SRC -> SNK POWER/FAST_ROLE_SWAP finished */
+			tcpm_ams_finish(port);
+
 		tcpm_set_state(port, SNK_DISCOVERY, 0);
 		break;
 	case SNK_DISCOVERY:
@@ -3437,7 +3763,7 @@ static void run_state_machine(struct tcpm_port *port)
 		 */
 		if (port->vbus_never_low) {
 			port->vbus_never_low = false;
-			tcpm_set_state(port, SOFT_RESET_SEND,
+			tcpm_set_state(port, SNK_SOFT_RESET,
 				       PD_T_SINK_WAIT_CAP);
 		} else {
 			tcpm_set_state(port, hard_reset_state(port),
@@ -3490,9 +3816,23 @@ static void run_state_machine(struct tcpm_port *port)
 
 		tcpm_swap_complete(port, 0);
 		tcpm_typec_connect(port);
-		tcpm_check_send_discover(port);
 		mod_enable_frs_delayed_work(port, 0);
 		tcpm_pps_complete(port, port->pps_status);
+
+		if (port->ams != NONE_AMS)
+			tcpm_ams_finish(port);
+		/*
+		 * If previous AMS is interrupted, switch to the upcoming
+		 * state.
+		 */
+		if (port->upcoming_state != INVALID_STATE) {
+			upcoming_state = port->upcoming_state;
+			port->upcoming_state = INVALID_STATE;
+			tcpm_set_state(port, upcoming_state, 0);
+			break;
+		}
+
+		tcpm_check_send_discover(port);
 		power_supply_changed(port->psy);
 		break;
 
@@ -3513,8 +3853,14 @@ static void run_state_machine(struct tcpm_port *port)
 
 	/* Hard_Reset states */
 	case HARD_RESET_SEND:
-		tcpm_pd_transmit(port, TCPC_TX_HARD_RESET, NULL);
-		tcpm_set_state(port, HARD_RESET_START, 0);
+		if (port->ams != NONE_AMS)
+			tcpm_ams_finish(port);
+		/*
+		 * State machine will be directed to HARD_RESET_START,
+		 * thus set upcoming_state to INVALID_STATE.
+		 */
+		port->upcoming_state = INVALID_STATE;
+		tcpm_ams_start(port, HARD_RESET);
 		break;
 	case HARD_RESET_START:
 		port->sink_cap_done = false;
@@ -3558,6 +3904,8 @@ static void run_state_machine(struct tcpm_port *port)
 	case SRC_HARD_RESET_VBUS_ON:
 		tcpm_set_vconn(port, true);
 		tcpm_set_vbus(port, true);
+		if (port->ams == HARD_RESET)
+			tcpm_ams_finish(port);
 		port->tcpc->set_pd_rx(port->tcpc, true);
 		tcpm_set_attached_state(port, true);
 		tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
@@ -3579,6 +3927,8 @@ static void run_state_machine(struct tcpm_port *port)
 		tcpm_set_state(port, SNK_HARD_RESET_SINK_ON, PD_T_SAFE_0V);
 		break;
 	case SNK_HARD_RESET_WAIT_VBUS:
+		if (port->ams == HARD_RESET)
+			tcpm_ams_finish(port);
 		/* Assume we're disconnected if VBUS doesn't come back. */
 		tcpm_set_state(port, SNK_UNATTACHED,
 			       PD_T_SRC_RECOVER_MAX + PD_T_SRC_TURN_ON);
@@ -3606,6 +3956,8 @@ static void run_state_machine(struct tcpm_port *port)
 					       5000);
 			tcpm_set_charge(port, true);
 		}
+		if (port->ams == HARD_RESET)
+			tcpm_ams_finish(port);
 		tcpm_set_attached_state(port, true);
 		tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V);
 		tcpm_set_state(port, SNK_STARTUP, 0);
@@ -3616,10 +3968,19 @@ static void run_state_machine(struct tcpm_port *port)
 		port->message_id = 0;
 		port->rx_msgid = -1;
 		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
-		if (port->pwr_role == TYPEC_SOURCE)
-			tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0);
-		else
+		if (port->pwr_role == TYPEC_SOURCE) {
+			port->upcoming_state = SRC_SEND_CAPABILITIES;
+			tcpm_ams_start(port, POWER_NEGOTIATION);
+		} else {
 			tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
+		}
+		break;
+	case SRC_SOFT_RESET_WAIT_SNK_TX:
+	case SNK_SOFT_RESET:
+		if (port->ams != NONE_AMS)
+			tcpm_ams_finish(port);
+		port->upcoming_state = SOFT_RESET_SEND;
+		tcpm_ams_start(port, SOFT_RESET_AMS);
 		break;
 	case SOFT_RESET_SEND:
 		port->message_id = 0;
@@ -3886,6 +4247,19 @@ static void run_state_machine(struct tcpm_port *port)
 			       tcpm_default_state(port),
 			       port->vbus_present ? PD_T_PS_SOURCE_OFF : 0);
 		break;
+
+	/* AMS intermediate state */
+	case AMS_START:
+		if (port->upcoming_state == INVALID_STATE) {
+			tcpm_set_state(port, port->pwr_role == TYPEC_SOURCE ?
+				       SRC_READY : SNK_READY, 0);
+			break;
+		}
+
+		upcoming_state = port->upcoming_state;
+		port->upcoming_state = INVALID_STATE;
+		tcpm_set_state(port, upcoming_state, 0);
+		break;
 	default:
 		WARN(1, "Unexpected port state %d\n", port->state);
 		break;
@@ -4313,6 +4687,8 @@ static void _tcpm_pd_hard_reset(struct tcpm_port *port)
 	if (port->bist_request == BDO_MODE_TESTDATA && port->tcpc->set_bist_data)
 		port->tcpc->set_bist_data(port->tcpc, false);
 
+	if (port->ams != NONE_AMS)
+		port->ams = NONE_AMS;
 	/*
 	 * If we keep receiving hard reset requests, executing the hard reset
 	 * must have failed. Revert to error recovery if that happens.
@@ -4363,10 +4739,16 @@ static void tcpm_pd_event_handler(struct kthread_work *work)
 				_tcpm_cc_change(port, cc1, cc2);
 		}
 		if (events & TCPM_FRS_EVENT) {
-			if (port->state == SNK_READY)
-				tcpm_set_state(port, FR_SWAP_SEND, 0);
-			else
+			if (port->state == SNK_READY) {
+				int ret;
+
+				port->upcoming_state = FR_SWAP_SEND;
+				ret = tcpm_ams_start(port, FAST_ROLE_SWAP);
+				if (ret == -EAGAIN)
+					port->upcoming_state = INVALID_STATE;
+			} else {
 				tcpm_log(port, "Discarding FRS_SIGNAL! Not in sink ready");
+			}
 		}
 		if (events & TCPM_SOURCING_VBUS) {
 			tcpm_log(port, "sourcing vbus");
@@ -4435,6 +4817,7 @@ EXPORT_SYMBOL_GPL(tcpm_sourcing_vbus);
 static void tcpm_enable_frs_work(struct kthread_work *work)
 {
 	struct tcpm_port *port = container_of(work, struct tcpm_port, enable_frs);
+	int ret;
 
 	mutex_lock(&port->lock);
 	/* Not FRS capable */
@@ -4449,9 +4832,14 @@ static void tcpm_enable_frs_work(struct kthread_work *work)
 	if (port->state != SNK_READY || port->vdm_state != VDM_STATE_DONE || port->send_discover)
 		goto resched;
 
-	tcpm_set_state(port, GET_SINK_CAP, 0);
-	port->sink_cap_done = true;
-
+	port->upcoming_state = GET_SINK_CAP;
+	ret = tcpm_ams_start(port, GET_SINK_CAPABILITIES);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+	} else {
+		port->sink_cap_done = true;
+		goto unlock;
+	}
 resched:
 	mod_enable_frs_delayed_work(port, GET_SINK_CAP_RETRY_MS);
 unlock:
@@ -4501,7 +4889,12 @@ static int tcpm_dr_set(struct typec_port *p, enum typec_data_role data)
 		port->non_pd_role_swap = true;
 		tcpm_set_state(port, PORT_RESET, 0);
 	} else {
-		tcpm_set_state(port, DR_SWAP_SEND, 0);
+		port->upcoming_state = DR_SWAP_SEND;
+		ret = tcpm_ams_start(port, DATA_ROLE_SWAP);
+		if (ret == -EAGAIN) {
+			port->upcoming_state = INVALID_STATE;
+			goto port_unlock;
+		}
 	}
 
 	port->swap_status = 0;
@@ -4547,10 +4940,16 @@ static int tcpm_pr_set(struct typec_port *p, enum typec_role role)
 		goto port_unlock;
 	}
 
+	port->upcoming_state = PR_SWAP_SEND;
+	ret = tcpm_ams_start(port, POWER_ROLE_SWAP);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+		goto port_unlock;
+	}
+
 	port->swap_status = 0;
 	port->swap_pending = true;
 	reinit_completion(&port->swap_complete);
-	tcpm_set_state(port, PR_SWAP_SEND, 0);
 	mutex_unlock(&port->lock);
 
 	if (!wait_for_completion_timeout(&port->swap_complete,
@@ -4586,10 +4985,16 @@ static int tcpm_vconn_set(struct typec_port *p, enum typec_role role)
 		goto port_unlock;
 	}
 
+	port->upcoming_state = VCONN_SWAP_SEND;
+	ret = tcpm_ams_start(port, VCONN_SWAP);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+		goto port_unlock;
+	}
+
 	port->swap_status = 0;
 	port->swap_pending = true;
 	reinit_completion(&port->swap_complete);
-	tcpm_set_state(port, VCONN_SWAP_SEND, 0);
 	mutex_unlock(&port->lock);
 
 	if (!wait_for_completion_timeout(&port->swap_complete,
@@ -4654,6 +5059,13 @@ static int tcpm_pps_set_op_curr(struct tcpm_port *port, u16 op_curr)
 		goto port_unlock;
 	}
 
+	port->upcoming_state = SNK_NEGOTIATE_PPS_CAPABILITIES;
+	ret = tcpm_ams_start(port, POWER_NEGOTIATION);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+		goto port_unlock;
+	}
+
 	/* Round down operating current to align with PPS valid steps */
 	op_curr = op_curr - (op_curr % RDO_PROG_CURR_MA_STEP);
 
@@ -4661,7 +5073,6 @@ static int tcpm_pps_set_op_curr(struct tcpm_port *port, u16 op_curr)
 	port->pps_data.op_curr = op_curr;
 	port->pps_status = 0;
 	port->pps_pending = true;
-	tcpm_set_state(port, SNK_NEGOTIATE_PPS_CAPABILITIES, 0);
 	mutex_unlock(&port->lock);
 
 	if (!wait_for_completion_timeout(&port->pps_complete,
@@ -4710,6 +5121,13 @@ static int tcpm_pps_set_out_volt(struct tcpm_port *port, u16 out_volt)
 		goto port_unlock;
 	}
 
+	port->upcoming_state = SNK_NEGOTIATE_PPS_CAPABILITIES;
+	ret = tcpm_ams_start(port, POWER_NEGOTIATION);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+		goto port_unlock;
+	}
+
 	/* Round down output voltage to align with PPS valid steps */
 	out_volt = out_volt - (out_volt % RDO_PROG_VOLT_MV_STEP);
 
@@ -4717,7 +5135,6 @@ static int tcpm_pps_set_out_volt(struct tcpm_port *port, u16 out_volt)
 	port->pps_data.out_volt = out_volt;
 	port->pps_status = 0;
 	port->pps_pending = true;
-	tcpm_set_state(port, SNK_NEGOTIATE_PPS_CAPABILITIES, 0);
 	mutex_unlock(&port->lock);
 
 	if (!wait_for_completion_timeout(&port->pps_complete,
@@ -4757,6 +5174,16 @@ static int tcpm_pps_activate(struct tcpm_port *port, bool activate)
 		goto port_unlock;
 	}
 
+	if (activate)
+		port->upcoming_state = SNK_NEGOTIATE_PPS_CAPABILITIES;
+	else
+		port->upcoming_state = SNK_NEGOTIATE_CAPABILITIES;
+	ret = tcpm_ams_start(port, POWER_NEGOTIATION);
+	if (ret == -EAGAIN) {
+		port->upcoming_state = INVALID_STATE;
+		goto port_unlock;
+	}
+
 	reinit_completion(&port->pps_complete);
 	port->pps_status = 0;
 	port->pps_pending = true;
@@ -4765,9 +5192,6 @@ static int tcpm_pps_activate(struct tcpm_port *port, bool activate)
 	if (activate) {
 		port->pps_data.out_volt = port->supply_voltage;
 		port->pps_data.op_curr = port->current_limit;
-		tcpm_set_state(port, SNK_NEGOTIATE_PPS_CAPABILITIES, 0);
-	} else {
-		tcpm_set_state(port, SNK_NEGOTIATE_CAPABILITIES, 0);
 	}
 	mutex_unlock(&port->lock);
 
diff --git a/include/linux/usb/pd.h b/include/linux/usb/pd.h
index bb9a782e1411..79599b90ba55 100644
--- a/include/linux/usb/pd.h
+++ b/include/linux/usb/pd.h
@@ -479,6 +479,7 @@ static inline unsigned int rdo_max_power(u32 rdo)
 #define PD_T_NEWSRC		250	/* Maximum of 275ms */
 #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_DRP_TRY		100	/* 75 - 150 ms */
 #define PD_T_DRP_TRYWAIT	600	/* 400 - 800 ms */
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index f4a18427f5c4..3af99f85e8b9 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -19,6 +19,10 @@ enum typec_cc_status {
 	TYPEC_CC_RP_3_0,
 };
 
+/* Collision Avoidance */
+#define SINK_TX_NG	TYPEC_CC_RP_1_5
+#define SINK_TX_OK	TYPEC_CC_RP_3_0
+
 enum typec_cc_polarity {
 	TYPEC_POLARITY_CC1,
 	TYPEC_POLARITY_CC2,
-- 
2.30.0.284.gd98b1dd5eaa7-goog

[PATCH v6 2/3] usb: typec: tcpm: Protocol Error handling

[Kyle Tso]

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.

Signed-off-by: Kyle Tso <kyletso@google.com>
---
changelog since v5:
 - removed the signed-off
 - modified the coding style suggested from Heikki
 - modified more coding style problems (line wrapping limit)

 drivers/usb/typec/tcpm/tcpm.c | 335 +++++++++++++++++++++++++---------
 include/linux/usb/pd.h        |   1 +
 2 files changed, 246 insertions(+), 90 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 2b16d2764092..70922723da4b 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -143,7 +143,8 @@
 	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),				\
@@ -433,6 +434,7 @@ struct tcpm_port {
 	/* 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
@@ -1213,7 +1215,8 @@ static int tcpm_ams_start(struct tcpm_port *port, enum tcpm_ams ams)
 
 	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]);
@@ -1231,11 +1234,10 @@ static int tcpm_ams_start(struct tcpm_port *port, enum tcpm_ams 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)
@@ -1452,6 +1454,9 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 	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) {
@@ -1537,22 +1542,37 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 				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;
 	}
 
@@ -1588,8 +1608,12 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
 		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
@@ -2039,6 +2063,71 @@ static int tcpm_set_auto_vbus_discharge_threshold(struct tcpm_port *port,
 	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)
 {
@@ -2052,9 +2141,6 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 
 	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]);
 
@@ -2070,12 +2156,26 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 		 * 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
@@ -2089,30 +2189,48 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 		 * 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... */
@@ -2133,16 +2251,22 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 
 		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);
@@ -2150,10 +2274,17 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 	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;
 	}
 }
@@ -2178,26 +2309,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 	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;
@@ -2236,6 +2351,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			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;
@@ -2282,6 +2402,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			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;
@@ -2298,8 +2423,6 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			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) {
@@ -2322,57 +2445,45 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			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:
@@ -2380,10 +2491,19 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 	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;
 	}
 }
@@ -2395,11 +2515,13 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 	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;
 	}
@@ -2412,16 +2534,18 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 		 */
 		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:
@@ -2435,10 +2559,11 @@ static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
 	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;
 	}
 }
@@ -2551,7 +2676,12 @@ static bool tcpm_send_queued_message(struct tcpm_port *port)
 			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);
@@ -2561,8 +2691,11 @@ static bool tcpm_send_queued_message(struct tcpm_port *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:
@@ -3581,6 +3714,11 @@ static void run_state_machine(struct tcpm_port *port)
 
 		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.
@@ -3821,6 +3959,11 @@ static void run_state_machine(struct tcpm_port *port)
 
 		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.
@@ -3968,6 +4111,7 @@ static void run_state_machine(struct tcpm_port *port)
 		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);
@@ -4004,6 +4148,7 @@ static void run_state_machine(struct tcpm_port *port)
 		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:
@@ -4016,6 +4161,7 @@ static void run_state_machine(struct tcpm_port *port)
 				       TYPEC_HOST);
 			port->send_discover = true;
 		}
+		tcpm_ams_finish(port);
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 
@@ -4143,6 +4289,7 @@ static void run_state_machine(struct tcpm_port *port)
 
 	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:
@@ -4260,6 +4407,12 @@ static void run_state_machine(struct tcpm_port *port)
 		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);
 		break;
@@ -4689,6 +4842,8 @@ static void _tcpm_pd_hard_reset(struct tcpm_port *port)
 
 	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.
diff --git a/include/linux/usb/pd.h b/include/linux/usb/pd.h
index 79599b90ba55..272454f9cd67 100644
--- a/include/linux/usb/pd.h
+++ b/include/linux/usb/pd.h
@@ -480,6 +480,7 @@ static inline unsigned int rdo_max_power(u32 rdo)
 #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 */
-- 
2.30.0.284.gd98b1dd5eaa7-goog

[PATCH v6 3/3] usb: typec: tcpm: Respond Wait if VDM state machine is running

[Kyle Tso]

Port partner could send PR_SWAP/DR_SWAP/VCONN_SWAP/Request just after it
enters Ready states. This will cause conficts if the port is going to
send DISC_IDENT in the Ready states of TCPM. Set a flag indicating that
the state machine is processing VDM and respond Wait messages until the
VDM state machine stops.

Signed-off-by: Kyle Tso <kyletso@google.com>
---
Changelog since v5:
 - no change

 drivers/usb/typec/tcpm/tcpm.c | 80 ++++++++++++++++++++++++++++++++---
 1 file changed, 73 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 70922723da4b..0dd932fe08d0 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -352,6 +352,7 @@ struct tcpm_port {
 	struct hrtimer enable_frs_timer;
 	struct kthread_work enable_frs;
 	bool state_machine_running;
+	bool vdm_sm_running;
 
 	struct completion tx_complete;
 	enum tcpm_transmit_status tx_status;
@@ -1526,6 +1527,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 				rlen = 1;
 			} else {
 				tcpm_register_partner_altmodes(port);
+				port->vdm_sm_running = false;
 			}
 			break;
 		case CMD_ENTER_MODE:
@@ -1569,10 +1571,12 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
 			rlen = 1;
 			break;
 		}
+		port->vdm_sm_running = false;
 		break;
 	default:
 		response[0] = p[0] | VDO_CMDT(CMDT_RSP_NAK);
 		rlen = 1;
+		port->vdm_sm_running = false;
 		break;
 	}
 
@@ -1739,6 +1743,8 @@ static void vdm_run_state_machine(struct tcpm_port *port)
 			switch (PD_VDO_CMD(vdo_hdr)) {
 			case CMD_DISCOVER_IDENT:
 				res = tcpm_ams_start(port, DISCOVER_IDENTITY);
+				if (res == 0)
+					port->send_discover = false;
 				break;
 			case CMD_DISCOVER_SVID:
 				res = tcpm_ams_start(port, DISCOVER_SVIDS);
@@ -1763,8 +1769,10 @@ static void vdm_run_state_machine(struct tcpm_port *port)
 				break;
 			}
 
-			if (res < 0)
+			if (res < 0) {
+				port->vdm_sm_running = false;
 				return;
+			}
 		}
 
 		port->vdm_state = VDM_STATE_SEND_MESSAGE;
@@ -1843,6 +1851,9 @@ static void vdm_state_machine_work(struct kthread_work *work)
 		 port->vdm_state != VDM_STATE_BUSY &&
 		 port->vdm_state != VDM_STATE_SEND_MESSAGE);
 
+	if (port->vdm_state == VDM_STATE_ERR_TMOUT)
+		port->vdm_sm_running = false;
+
 	mutex_unlock(&port->lock);
 }
 
@@ -2226,6 +2237,12 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
 		}
 
 		port->sink_request = le32_to_cpu(msg->payload[0]);
+
+		if (port->vdm_sm_running && port->explicit_contract) {
+			tcpm_pd_handle_msg(port, PD_MSG_CTRL_WAIT, port->ams);
+			break;
+		}
+
 		if (port->state == SRC_SEND_CAPABILITIES)
 			tcpm_set_state(port, SRC_NEGOTIATE_CAPABILITIES, 0);
 		else
@@ -2328,6 +2345,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 								       TYPEC_PWR_MODE_PD,
 								       port->pps_data.active,
 								       port->supply_voltage);
+				/* Set VDM running flag ASAP */
+				if (port->data_role == TYPEC_HOST &&
+				    port->send_discover)
+					port->vdm_sm_running = true;
 				tcpm_set_state(port, SNK_READY, 0);
 			} else {
 				/*
@@ -2365,10 +2386,14 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 		switch (port->state) {
 		case SNK_NEGOTIATE_CAPABILITIES:
 			/* USB PD specification, Figure 8-43 */
-			if (port->explicit_contract)
+			if (port->explicit_contract) {
 				next_state = SNK_READY;
-			else
+				if (port->data_role == TYPEC_HOST &&
+				    port->send_discover)
+					port->vdm_sm_running = true;
+			} else {
 				next_state = SNK_WAIT_CAPABILITIES;
+			}
 			tcpm_set_state(port, next_state, 0);
 			break;
 		case SNK_NEGOTIATE_PPS_CAPABILITIES:
@@ -2377,6 +2402,11 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			port->pps_data.op_curr = port->current_limit;
 			port->pps_status = (type == PD_CTRL_WAIT ?
 					    -EAGAIN : -EOPNOTSUPP);
+
+			if (port->data_role == TYPEC_HOST &&
+			    port->send_discover)
+				port->vdm_sm_running = true;
+
 			tcpm_set_state(port, SNK_READY, 0);
 			break;
 		case DR_SWAP_SEND:
@@ -2433,6 +2463,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 			}
 			break;
 		case DR_SWAP_SEND:
+			if (port->data_role == TYPEC_DEVICE &&
+			    port->send_discover)
+				port->vdm_sm_running = true;
+
 			tcpm_set_state(port, DR_SWAP_CHANGE_DR, 0);
 			break;
 		case PR_SWAP_SEND:
@@ -2463,26 +2497,43 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 		 * 6.3.9: If an alternate mode is active, a request to swap
 		 * alternate modes shall trigger a port reset.
 		 */
-		if (port->typec_caps.data != TYPEC_PORT_DRD)
+		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
+		} else {
+			if (port->vdm_sm_running) {
+				tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
+				break;
+			}
+
 			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)
+		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
+		} else {
+			if (port->vdm_sm_running) {
+				tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
+				break;
+			}
+
 			tcpm_pd_handle_state(port, PR_SWAP_ACCEPT, POWER_ROLE_SWAP, 0);
+		}
 		break;
 	case PD_CTRL_VCONN_SWAP:
+		if (port->vdm_sm_running) {
+			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:
@@ -3346,6 +3397,7 @@ static void tcpm_reset_port(struct tcpm_port *port)
 	}
 	port->in_ams = false;
 	port->ams = NONE_AMS;
+	port->vdm_sm_running = false;
 	tcpm_unregister_altmodes(port);
 	tcpm_typec_disconnect(port);
 	port->attached = false;
@@ -4144,6 +4196,9 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case DR_SWAP_ACCEPT:
 		tcpm_pd_send_control(port, PD_CTRL_ACCEPT);
+		/* Set VDM state machine running flag ASAP */
+		if (port->data_role == TYPEC_DEVICE && port->send_discover)
+			port->vdm_sm_running = true;
 		tcpm_set_state_cond(port, DR_SWAP_CHANGE_DR, 0);
 		break;
 	case DR_SWAP_SEND_TIMEOUT:
@@ -4299,6 +4354,8 @@ static void run_state_machine(struct tcpm_port *port)
 		break;
 	case VCONN_SWAP_SEND_TIMEOUT:
 		tcpm_swap_complete(port, -ETIMEDOUT);
+		if (port->data_role == TYPEC_HOST && port->send_discover)
+			port->vdm_sm_running = true;
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 	case VCONN_SWAP_START:
@@ -4314,10 +4371,14 @@ static void run_state_machine(struct tcpm_port *port)
 	case VCONN_SWAP_TURN_ON_VCONN:
 		tcpm_set_vconn(port, true);
 		tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
+		if (port->data_role == TYPEC_HOST && port->send_discover)
+			port->vdm_sm_running = true;
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 	case VCONN_SWAP_TURN_OFF_VCONN:
 		tcpm_set_vconn(port, false);
+		if (port->data_role == TYPEC_HOST && port->send_discover)
+			port->vdm_sm_running = true;
 		tcpm_set_state(port, ready_state(port), 0);
 		break;
 
@@ -4325,6 +4386,8 @@ static void run_state_machine(struct tcpm_port *port)
 	case PR_SWAP_CANCEL:
 	case VCONN_SWAP_CANCEL:
 		tcpm_swap_complete(port, port->swap_status);
+		if (port->data_role == TYPEC_HOST && port->send_discover)
+			port->vdm_sm_running = true;
 		if (port->pwr_role == TYPEC_SOURCE)
 			tcpm_set_state(port, SRC_READY, 0);
 		else
@@ -4654,6 +4717,9 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port)
 	switch (port->state) {
 	case SNK_TRANSITION_SINK_VBUS:
 		port->explicit_contract = true;
+		/* Set the VDM flag ASAP */
+		if (port->data_role == TYPEC_HOST && port->send_discover)
+			port->vdm_sm_running = true;
 		tcpm_set_state(port, SNK_READY, 0);
 		break;
 	case SNK_DISCOVERY:
-- 
2.30.0.284.gd98b1dd5eaa7-goog

Re: [PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Hans de Goede]

Hi All,

On 1/14/21 3:50 PM, Kyle Tso wrote:
> v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com
> 
> "usb: typec: tcpm: AMS and Collision Avoidance"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - added FR_SWAP AMS handling
> 
> "usb: typec: tcpm: Protocol Error handling"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - modified more coding style problems (line wrapping limit)
> 
> "usb: typec: tcpm: Respond Wait if VDM state machine is running"
>  - no change

I'm afraid that my testing of this patch-set has been delayed due to a
5.11 regression which I'm chasing down. I have put a task for this
in my calendar for Wednesday Jan 20.

Regards,

Hans

Re: [PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Hans de Goede]

Hi,

On 1/14/21 3:50 PM, Kyle Tso wrote:
> v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com
> 
> "usb: typec: tcpm: AMS and Collision Avoidance"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - added FR_SWAP AMS handling
> 
> "usb: typec: tcpm: Protocol Error handling"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - modified more coding style problems (line wrapping limit)
> 
> "usb: typec: tcpm: Respond Wait if VDM state machine is running"
>  - no change

I've finally gotten around to testing this. I'm happy to
report that the power-role swapping regression seen in one
of the older versions of this patch-set is gone.

So the entire series is:
Tested-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans





> 
> -------------------------------------------------------------------
> 
> Kyle Tso (3):
>   usb: typec: tcpm: AMS and Collision Avoidance
>   usb: typec: tcpm: Protocol Error handling
>   usb: typec: tcpm: Respond Wait if VDM state machine is running
> 
>  drivers/usb/typec/tcpm/tcpm.c | 1001 +++++++++++++++++++++++++++------
>  include/linux/usb/pd.h        |    2 +
>  include/linux/usb/tcpm.h      |    4 +
>  3 files changed, 829 insertions(+), 178 deletions(-)
> 

Re: [PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Greg KH]

On Wed, Jan 20, 2021 at 02:45:02PM +0100, Hans de Goede wrote:
> Hi,
> 
> On 1/14/21 3:50 PM, Kyle Tso wrote:
> > v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com
> > 
> > "usb: typec: tcpm: AMS and Collision Avoidance"
> >  - removed the signed-off
> >  - modified the coding style suggested from Heikki
> >  - added FR_SWAP AMS handling
> > 
> > "usb: typec: tcpm: Protocol Error handling"
> >  - removed the signed-off
> >  - modified the coding style suggested from Heikki
> >  - modified more coding style problems (line wrapping limit)
> > 
> > "usb: typec: tcpm: Respond Wait if VDM state machine is running"
> >  - no change
> 
> I've finally gotten around to testing this. I'm happy to
> report that the power-role swapping regression seen in one
> of the older versions of this patch-set is gone.
> 
> So the entire series is:
> Tested-by: Hans de Goede <hdegoede@redhat.com>

Thanks for testing and the review.

Heikki, any thoughts?

thanks,

greg k-h

Re: [PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Heikki Krogerus]

On Wed, Jan 20, 2021 at 06:17:35PM +0100, Greg KH wrote:
> On Wed, Jan 20, 2021 at 02:45:02PM +0100, Hans de Goede wrote:
> > Hi,
> > 
> > On 1/14/21 3:50 PM, Kyle Tso wrote:
> > > v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com
> > > 
> > > "usb: typec: tcpm: AMS and Collision Avoidance"
> > >  - removed the signed-off
> > >  - modified the coding style suggested from Heikki
> > >  - added FR_SWAP AMS handling
> > > 
> > > "usb: typec: tcpm: Protocol Error handling"
> > >  - removed the signed-off
> > >  - modified the coding style suggested from Heikki
> > >  - modified more coding style problems (line wrapping limit)
> > > 
> > > "usb: typec: tcpm: Respond Wait if VDM state machine is running"
> > >  - no change
> > 
> > I've finally gotten around to testing this. I'm happy to
> > report that the power-role swapping regression seen in one
> > of the older versions of this patch-set is gone.
> > 
> > So the entire series is:
> > Tested-by: Hans de Goede <hdegoede@redhat.com>
> 
> Thanks for testing and the review.
> 
> Heikki, any thoughts?

Looks good to me.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

-- 
heikki

Re: [PATCH v6 0/3] AMS, Collision Avoidance, and Protocol Error

[Guenter Roeck]

On 1/14/21 6:50 AM, Kyle Tso wrote:
> v5 https://lore.kernel.org/r/20210105163927.1376770-1-kyletso@google.com
> 
> "usb: typec: tcpm: AMS and Collision Avoidance"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - added FR_SWAP AMS handling
> 
> "usb: typec: tcpm: Protocol Error handling"
>  - removed the signed-off
>  - modified the coding style suggested from Heikki
>  - modified more coding style problems (line wrapping limit)
> 
> "usb: typec: tcpm: Respond Wait if VDM state machine is running"
>  - no change
> 
> -------------------------------------------------------------------
> 
> Kyle Tso (3):
>   usb: typec: tcpm: AMS and Collision Avoidance
>   usb: typec: tcpm: Protocol Error handling
>   usb: typec: tcpm: Respond Wait if VDM state machine is running
> 
>  drivers/usb/typec/tcpm/tcpm.c | 1001 +++++++++++++++++++++++++++------
>  include/linux/usb/pd.h        |    2 +
>  include/linux/usb/tcpm.h      |    4 +
>  3 files changed, 829 insertions(+), 178 deletions(-)
> 

For the series:

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Guenter