tcpmv2: disable receive of SOP' during VCONN swap

The USB PD specification indicates that the initial VCONN source shall
cease source VCONN within tVCONNSourceOff (25 ms) after receiving
PS_RDY. Not all partners wait after sending PS_RDY before trying to
communicate with the cable.

BUG=b:163478172, b:163143427
BRANCH=none
TEST=make buildall
TEST=Connect 2 Volteers together and force VCONN swaps confirming the
sequence completes normally.

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: I14720f033c5f6e9caed9c4fe3bfa11e5c046116e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2381030
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Commit-Queue: Denis Brockus <dbrockus@chromium.org>

13 files changed, 130 insertions, 43 deletions

diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index c90d98a75c..7e76c15e1c 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -5269,6 +5269,23 @@ static void pe_vcs_evaluate_swap_entry(int port)
 		/* NOTE: PE_VCS_Accept_Swap State embedded here */
 		PE_SET_FLAG(port, PE_FLAGS_ACCEPT);
 		send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_ACCEPT);
+
+		/*
+		 * The USB PD 3.0 spec indicates that the initial VCONN source
+		 * shall cease sourcing VCONN within tVCONNSourceOff (25ms)
+		 * after receiving the PS_RDY message. However, some partners
+		 * begin sending SOP' messages only 1 ms after sending PS_RDY
+		 * during VCONN swap.
+		 *
+		 * Preemptively disable receipt of SOP' and SOP'' messages while
+		 * we wait for PS_RDY so we don't attempt to process messages
+		 * directed at the cable. If the partner fails to send PS_RDY we
+		 * perform a hard reset so no need to re-enable SOP' messages.
+		 *
+		 * We continue to source VCONN while we wait as required by the
+		 * spec.
+		 */
+		tcpm_sop_prime_disable(port);
 	}
 }
 
@@ -5333,12 +5350,18 @@ static void pe_vcs_send_swap_run(int port)
 			 */
 			if (type == PD_CTRL_ACCEPT) {
 				pe[port].vconn_swap_counter = 0;
-				if (tc_is_vconn_src(port))
+				if (tc_is_vconn_src(port)) {
+					/*
+					 * Prevent receiving any SOP' and SOP''
+					 * messages while a swap is in progress.
+					 */
+					tcpm_sop_prime_disable(port);
 					set_state_pe(port,
 						PE_VCS_WAIT_FOR_VCONN_SWAP);
-				else
+				} else {
 					set_state_pe(port,
 						PE_VCS_TURN_ON_VCONN_SWAP);
+				}
 				return;
 			}
 			/*
diff --git a/driver/tcpm/anx7447.c b/driver/tcpm/anx7447.c
index f1fda87cf1..de9fb5dcfc 100644
--- a/driver/tcpm/anx7447.c
+++ b/driver/tcpm/anx7447.c
@@ -809,6 +809,9 @@ const struct tcpm_drv anx7447_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &anx7447_set_cc,
 	.set_polarity		= &anx7447_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/anx7688.c b/driver/tcpm/anx7688.c
index af585db562..1c6785f406 100644
--- a/driver/tcpm/anx7688.c
+++ b/driver/tcpm/anx7688.c
@@ -200,6 +200,9 @@ const struct tcpm_drv anx7688_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &tcpci_tcpm_set_cc,
 	.set_polarity		= &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/mt6370.c b/driver/tcpm/mt6370.c
index af11bcb11d..07ebeac7f9 100644
--- a/driver/tcpm/mt6370.c
+++ b/driver/tcpm/mt6370.c
@@ -195,6 +195,9 @@ const struct tcpm_drv mt6370_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &mt6370_set_cc,
 	.set_polarity		= &mt6370_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/nct38xx.c b/driver/tcpm/nct38xx.c
index ffd2a15b68..308cefe928 100644
--- a/driver/tcpm/nct38xx.c
+++ b/driver/tcpm/nct38xx.c
@@ -201,6 +201,9 @@ const struct tcpm_drv nct38xx_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &nct38xx_tcpm_set_cc,
 	.set_polarity		= &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/ps8xxx.c b/driver/tcpm/ps8xxx.c
index 713977b1e7..9fb6d31544 100644
--- a/driver/tcpm/ps8xxx.c
+++ b/driver/tcpm/ps8xxx.c
@@ -572,6 +572,9 @@ const struct tcpm_drv ps8xxx_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &tcpci_tcpm_set_cc,
 	.set_polarity		= &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/raa489000.c b/driver/tcpm/raa489000.c
index ae6aef2269..632c17c78b 100644
--- a/driver/tcpm/raa489000.c
+++ b/driver/tcpm/raa489000.c
@@ -207,6 +207,9 @@ const struct tcpm_drv raa489000_tcpm_drv = {
 	.select_rp_value        = &tcpci_tcpm_select_rp_value,
 	.set_cc                 = &raa489000_tcpm_set_cc,
 	.set_polarity           = &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn              = &tcpci_tcpm_set_vconn,
 	.set_msg_header         = &tcpci_tcpm_set_msg_header,
 	.set_rx_enable          = &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/rt1715.c b/driver/tcpm/rt1715.c
index 970af18984..cf98666058 100644
--- a/driver/tcpm/rt1715.c
+++ b/driver/tcpm/rt1715.c
@@ -55,6 +55,9 @@ const struct tcpm_drv rt1715_tcpm_drv = {
 	.select_rp_value = &tcpci_tcpm_select_rp_value,
 	.set_cc = &tcpci_tcpm_set_cc,
 	.set_polarity = &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn = &tcpci_tcpm_set_vconn,
 	.set_msg_header = &tcpci_tcpm_set_msg_header,
 	.set_rx_enable = &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/tcpci.c b/driver/tcpm/tcpci.c
index 008f3bd589..64de918dff 100644
--- a/driver/tcpm/tcpci.c
+++ b/driver/tcpm/tcpci.c
@@ -25,10 +25,10 @@
 #define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)
 #define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)
 
-#ifdef CONFIG_USB_PD_DECODE_SOP
-static int vconn_en[CONFIG_USB_PD_PORT_MAX_COUNT];
-static int rx_en[CONFIG_USB_PD_PORT_MAX_COUNT];
-#endif
+STATIC_IF(CONFIG_USB_PD_DECODE_SOP)
+	int sop_prime_en[CONFIG_USB_PD_PORT_MAX_COUNT];
+STATIC_IF(CONFIG_USB_PD_DECODE_SOP)
+	int rx_en[CONFIG_USB_PD_PORT_MAX_COUNT];
 
 #define TCPC_FLAGS_VSAFE0V(_flags) \
 	((_flags & TCPC_FLAGS_TCPCI_REV2_0) && \
@@ -608,17 +608,10 @@ int tcpci_tcpm_set_src_ctrl(int port, int enable)
 }
 #endif
 
-int tcpci_tcpm_set_vconn(int port, int enable)
+__maybe_unused static int tpcm_set_sop_prime_enable(int port, int enable)
 {
-	int reg, rv;
-
-	rv = tcpc_read(port, TCPC_REG_POWER_CTRL, &reg);
-	if (rv)
-		return rv;
-
-#ifdef CONFIG_USB_PD_DECODE_SOP
-	/* save vconn */
-	vconn_en[port] = enable;
+	/* save SOP'/SOP'' enable state */
+	sop_prime_en[port] = enable;
 
 	if (rx_en[port]) {
 		int detect_sop_en = TCPC_REG_RX_DETECT_SOP_HRST_MASK;
@@ -628,9 +621,31 @@ int tcpci_tcpm_set_vconn(int port, int enable)
 				TCPC_REG_RX_DETECT_SOP_SOPP_SOPPP_HRST_MASK;
 		}
 
-		tcpc_write(port, TCPC_REG_RX_DETECT, detect_sop_en);
+		return tcpc_write(port, TCPC_REG_RX_DETECT, detect_sop_en);
 	}
-#endif
+
+	return EC_SUCCESS;
+}
+
+__maybe_unused int tcpci_tcpm_sop_prime_disable(int port)
+{
+	return tpcm_set_sop_prime_enable(port, 0);
+}
+
+int tcpci_tcpm_set_vconn(int port, int enable)
+{
+	int reg, rv;
+
+	rv = tcpc_read(port, TCPC_REG_POWER_CTRL, &reg);
+	if (rv)
+		return rv;
+
+	if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP)) {
+		rv = tpcm_set_sop_prime_enable(port, enable);
+		if (rv)
+			return rv;
+	}
+
 	reg &= ~TCPC_REG_POWER_CTRL_VCONN(1);
 	reg |= TCPC_REG_POWER_CTRL_VCONN(enable);
 	return tcpc_write(port, TCPC_REG_POWER_CTRL, reg);
@@ -664,24 +679,24 @@ int tcpci_tcpm_set_rx_enable(int port, int enable)
 {
 	int detect_sop_en = 0;
 
-#ifdef CONFIG_USB_PD_DECODE_SOP
-	/* save rx_on */
-	rx_en[port] = enable;
-#endif
+	if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP)) {
+		/* save rx_on */
+		rx_en[port] = enable;
+	}
+
 
 	if (enable) {
 		detect_sop_en = TCPC_REG_RX_DETECT_SOP_HRST_MASK;
 
-#ifdef CONFIG_USB_PD_DECODE_SOP
-		/*
-		 * Only the VCONN Source is allowed to communicate
-		 * with the Cable Plugs.
-		 */
-
-		if (vconn_en[port])
+		if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP) &&
+			sop_prime_en[port]) {
+			/*
+			 * Only the VCONN Source is allowed to communicate
+			 * with the Cable Plugs.
+			 */
 			detect_sop_en =
 				TCPC_REG_RX_DETECT_SOP_SOPP_SOPPP_HRST_MASK;
-#endif
+		}
 	}
 
 	/* If enable, then set RX detect for SOP and HRST */
@@ -765,9 +780,7 @@ static int tcpci_rev1_0_tcpm_get_message_raw(int port, uint32_t *payload,
 					     int *head)
 {
 	int rv, cnt, reg = TCPC_REG_RX_DATA;
-#ifdef CONFIG_USB_PD_DECODE_SOP
 	int frm;
-#endif
 
 	rv = tcpc_read(port, TCPC_REG_RX_BYTE_CNT, &cnt);
 
@@ -782,21 +795,22 @@ static int tcpci_rev1_0_tcpm_get_message_raw(int port, uint32_t *payload,
 		goto clear;
 	}
 
-#ifdef CONFIG_USB_PD_DECODE_SOP
-	rv = tcpc_read(port, TCPC_REG_RX_BUF_FRAME_TYPE, &frm);
-	if (rv != EC_SUCCESS) {
-		rv = EC_ERROR_UNKNOWN;
-		goto clear;
+	if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP)) {
+		rv = tcpc_read(port, TCPC_REG_RX_BUF_FRAME_TYPE, &frm);
+		if (rv != EC_SUCCESS) {
+			rv = EC_ERROR_UNKNOWN;
+			goto clear;
+		}
 	}
-#endif
 
 	rv = tcpc_read16(port, TCPC_REG_RX_HDR, (int *)head);
 
-#ifdef CONFIG_USB_PD_DECODE_SOP
-	/* Encode message address in bits 31 to 28 */
-	*head &= 0x0000ffff;
-	*head |= PD_HEADER_SOP(frm);
-#endif
+	if (IS_ENABLED(CONFIG_USB_PD_DECODE_SOP)) {
+		/* Encode message address in bits 31 to 28 */
+		*head &= 0x0000ffff;
+		*head |= PD_HEADER_SOP(frm);
+	}
+
 	if (rv == EC_SUCCESS && cnt > 0) {
 		tcpc_read_block(port, reg, (uint8_t *)payload, cnt);
 	}
@@ -1726,6 +1740,9 @@ const struct tcpm_drv tcpci_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &tcpci_tcpm_set_cc,
 	.set_polarity		= &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/driver/tcpm/tcpci.h b/driver/tcpm/tcpci.h
index 914b143c41..db05c978e8 100644
--- a/driver/tcpm/tcpci.h
+++ b/driver/tcpm/tcpci.h
@@ -221,6 +221,7 @@ bool tcpci_tcpm_check_vbus_level(int port, enum vbus_level level);
 int tcpci_tcpm_select_rp_value(int port, int rp);
 int tcpci_tcpm_set_cc(int port, int pull);
 int tcpci_tcpm_set_polarity(int port, enum tcpc_cc_polarity polarity);
+int tcpci_tcpm_sop_prime_disable(int port);
 int tcpci_tcpm_set_vconn(int port, int enable);
 int tcpci_tcpm_set_msg_header(int port, int power_role, int data_role);
 int tcpci_tcpm_set_rx_enable(int port, int enable);
diff --git a/driver/tcpm/tcpm.h b/driver/tcpm/tcpm.h
index 4ab993dcc2..e1db30ecb8 100644
--- a/driver/tcpm/tcpm.h
+++ b/driver/tcpm/tcpm.h
@@ -193,6 +193,15 @@ static inline int tcpm_set_polarity(int port, enum tcpc_cc_polarity polarity)
 	return tcpc_config[port].drv->set_polarity(port, polarity);
 }
 
+static inline int tcpm_sop_prime_disable(int port)
+{
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	return tcpc_config[port].drv->sop_prime_disable(port);
+#else
+	return EC_SUCCESS;
+#endif
+}
+
 static inline int tcpm_set_vconn(int port, int enable)
 {
 	return tcpc_config[port].drv->set_vconn(port, enable);
diff --git a/driver/tcpm/tusb422.c b/driver/tcpm/tusb422.c
index 3ab95c9721..75ffcd1d43 100644
--- a/driver/tcpm/tusb422.c
+++ b/driver/tcpm/tusb422.c
@@ -158,6 +158,9 @@ const struct tcpm_drv tusb422_tcpm_drv = {
 	.select_rp_value	= &tcpci_tcpm_select_rp_value,
 	.set_cc			= &tusb422_tcpm_set_cc,
 	.set_polarity		= &tcpci_tcpm_set_polarity,
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	.sop_prime_disable	= &tcpci_tcpm_sop_prime_disable,
+#endif
 	.set_vconn		= &tcpci_tcpm_set_vconn,
 	.set_msg_header		= &tcpci_tcpm_set_msg_header,
 	.set_rx_enable		= &tcpci_tcpm_set_rx_enable,
diff --git a/include/usb_pd_tcpm.h b/include/usb_pd_tcpm.h
index bccea184e4..d6f89553fc 100644
--- a/include/usb_pd_tcpm.h
+++ b/include/usb_pd_tcpm.h
@@ -245,6 +245,19 @@ struct tcpm_drv {
 	 */
 	int (*set_polarity)(int port, enum tcpc_cc_polarity polarity);
 
+#ifdef CONFIG_USB_PD_DECODE_SOP
+	/**
+	 * Disable receive of SOP' and SOP'' messages. This is provided
+	 * separately from set_vconn so that we can preemptively disable
+	 * receipt of SOP' messages during a VCONN swap.
+	 *
+	 * @param port Type-C port number
+	 *
+	 * @return EC_SUCCESS or error
+	 */
+	int (*sop_prime_disable)(int port);
+#endif
+
 	/**
 	 * Set Vconn.
 	 *