tcpmv2: always issue SOP' soft reset

After entering a PD contract, always issue an SOP' soft reset before
sending any discovery VDMs to the cable.

BUG=b:172364575
BRANCH=volteer
TEST=connect monitor with emarked cable, verify SOP' soft reset is sent
when EC starts as SNK/DFP.
TEST=Connect monitor with non-emark cable. Verify SOP' soft reset is
sent once regardless of starting role.
TEST=Connect USB4 dock, verify USB4 entry.

Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: Id5026a2c8c9877b860e1356dd33763bad3e51841
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2596838
Reviewed-by: Diana Z <dzigterman@chromium.org>
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

5 files changed, 164 insertions, 21 deletions

diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index de8be98707..9659614d49 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -297,6 +297,7 @@ enum usb_pe_state {
 	PE_VCS_TURN_ON_VCONN_SWAP,
 	PE_VCS_TURN_OFF_VCONN_SWAP,
 	PE_VCS_SEND_PS_RDY_SWAP,
+	PE_VCS_CBL_SEND_SOFT_RESET,
 	PE_VDM_IDENTITY_REQUEST_CBL,
 	PE_INIT_PORT_VDM_IDENTITY_REQUEST,
 	PE_INIT_VDM_SVIDS_REQUEST,
@@ -413,6 +414,7 @@ __maybe_unused static const char * const pe_state_names[] = {
 	[PE_VCS_TURN_ON_VCONN_SWAP] = "PE_VCS_Turn_On_Vconn_Swap",
 	[PE_VCS_TURN_OFF_VCONN_SWAP] = "PE_VCS_Turn_Off_Vconn_Swap",
 	[PE_VCS_SEND_PS_RDY_SWAP] = "PE_VCS_Send_Ps_Rdy_Swap",
+	[PE_VCS_CBL_SEND_SOFT_RESET] = "PE_VCS_CBL_Send_Soft_Reset",
 #endif
 	[PE_VDM_IDENTITY_REQUEST_CBL] = "PE_VDM_Identity_Request_Cbl",
 	[PE_INIT_PORT_VDM_IDENTITY_REQUEST] =
@@ -1248,6 +1250,7 @@ void pe_report_error(int port, enum pe_error e, enum tcpm_transmit_type type)
 			get_state_pe(port) == PE_PRS_SRC_SNK_WAIT_SOURCE_ON ||
 			get_state_pe(port) == PE_SRC_DISABLED ||
 			get_state_pe(port) == PE_SRC_DISCOVERY ||
+			get_state_pe(port) == PE_VCS_CBL_SEND_SOFT_RESET ||
 			get_state_pe(port) == PE_VDM_IDENTITY_REQUEST_CBL) ||
 			(PE_CHK_FLAG(port, PE_FLAGS_FAST_ROLE_SWAP_PATH) &&
 			    get_state_pe(port) == PE_PRS_SNK_SRC_SEND_SWAP) ||
@@ -1685,6 +1688,18 @@ __maybe_unused static bool pe_attempt_port_discovery(int port)
 		}
 	}
 
+	/*
+	 * TODO(b/177001425): TCPMv2 - move SOP' soft reset check into
+	 * common_src_snk_dpm_requests()
+	 */
+	if (PE_CHK_DPM_REQUEST(port, DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND)) {
+		pe_set_dpm_curr_request(port,
+			DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND);
+		pe[port].tx_type = TCPC_TX_SOP_PRIME;
+		set_state_pe(port, PE_VCS_CBL_SEND_SOFT_RESET);
+		return true;
+	}
+
 	/* If mode entry was successful, disable the timer */
 	if (PE_CHK_FLAG(port, PE_FLAGS_VDM_SETUP_DONE)) {
 		pe[port].discover_identity_timer = TIMER_DISABLED;
@@ -1894,6 +1909,13 @@ static void pe_src_startup_entry(int port)
 	/* Reset the protocol layer */
 	prl_reset(port);
 
+	/*
+	 * Protocol layer reset clears the message IDs for all SOP types.
+	 * Indicate that a SOP' soft reset is required before any other
+	 * messages are sent to the cable.
+	 */
+	pd_dpm_request(port, DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND);
+
 	/* Set initial data role */
 	pe[port].data_role = pd_get_data_role(port);
 
@@ -2770,6 +2792,13 @@ static void pe_snk_startup_entry(int port)
 	/* Reset the protocol layer */
 	prl_reset(port);
 
+	/*
+	 * Protocol layer reset clears the message IDs for all SOP types.
+	 * Indicate that a SOP' soft reset is required before any other
+	 * messages are sent to the cable.
+	 */
+	pd_dpm_request(port, DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND);
+
 	/* Set initial data role */
 	pe[port].data_role = pd_get_data_role(port);
 
@@ -6169,6 +6198,13 @@ static void pe_vcs_send_ps_rdy_swap_run(int port)
 	/* TODO(b/152058087): TCPMv2: Break up pe_vcs_send_ps_rdy_swap */
 	switch (pe[port].sub) {
 	case PE_SUB0:
+
+		/*
+		 * TODO: use DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND to
+		 * send cable soft reset.
+		 */
+		PE_CLR_DPM_REQUEST(port, DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND);
+
 		/*
 		 * After a VCONN Swap the VCONN Source needs to reset
 		 * the Cable Plug’s Protocol Layer in order to ensure
@@ -6233,6 +6269,80 @@ static void pe_vcs_send_ps_rdy_swap_run(int port)
 		}
 	}
 }
+
+/*
+ * PE_VCS_CBL_SEND_SOFT_RESET
+ * Note - Entry is only when directed by the DPM. Protocol errors are handled
+ * by the PE_SEND_SOFT_RESET state.
+ */
+static void pe_vcs_cbl_send_soft_reset_entry(int port)
+{
+	print_current_state(port);
+
+	if (!pe_can_send_sop_prime(port)) {
+		/*
+		 * If we're not VCONN source, return the appropriate state.
+		 * A VCONN swap re-triggers sending SOP' soft reset
+		 */
+		if (pe_is_explicit_contract(port)) {
+			/* Return to PE_{SRC,SNK}_Ready state */
+			pe_set_ready_state(port);
+		} else {
+			/*
+			 * Not in Explicit Contract, so we must be a SRC,
+			 * return to PE_Src_Send_Capabilities.
+			 */
+			set_state_pe(port, PE_SRC_SEND_CAPABILITIES);
+		}
+		return;
+	}
+
+	send_ctrl_msg(port, TCPC_TX_SOP_PRIME, PD_CTRL_SOFT_RESET);
+	pe[port].sender_response_timer = TIMER_DISABLED;
+}
+
+static void pe_vcs_cbl_send_soft_reset_run(int port)
+{
+	bool cable_soft_reset_complete = false;
+
+	if (PE_CHK_FLAG(port, PE_FLAGS_TX_COMPLETE)) {
+		PE_CLR_FLAG(port, PE_FLAGS_TX_COMPLETE);
+		pe[port].sender_response_timer = get_time().val +
+						PD_T_SENDER_RESPONSE;
+	}
+
+	/* Got ACCEPT or REJECT from Cable Plug */
+	if (PE_CHK_FLAG(port, PE_FLAGS_MSG_RECEIVED)) {
+		PE_CLR_FLAG(port, PE_FLAGS_MSG_RECEIVED);
+		cable_soft_reset_complete = true;
+	}
+
+	/* No GoodCRC received, cable is not present */
+	if (PE_CHK_FLAG(port, PE_FLAGS_PROTOCOL_ERROR)) {
+		PE_CLR_FLAG(port, PE_FLAGS_PROTOCOL_ERROR);
+		/*
+		 * TODO(b/171823328): TCPMv2: Implement cable reset
+		 * Cable reset will only be done here if we know for certain
+		 * a cable is present (we've received the SOP' DiscId response).
+		 */
+		cable_soft_reset_complete = true;
+	}
+
+	if (cable_soft_reset_complete ||
+		get_time().val > pe[port].sender_response_timer) {
+		if (pe_is_explicit_contract(port)) {
+			/* Return to PE_{SRC,SNK}_Ready state */
+			pe_set_ready_state(port);
+		} else {
+			/*
+			 * Not in Explicit Contract, so we must be a SRC,
+			 * return to PE_Src_Send_Capabilities.
+			 */
+			set_state_pe(port, PE_SRC_SEND_CAPABILITIES);
+		}
+	}
+}
+
 #endif /* CONFIG_USBC_VCONN */
 
 /*
@@ -6749,6 +6859,10 @@ static const struct usb_state pe_states[] = {
 		.entry = pe_vcs_send_ps_rdy_swap_entry,
 		.run   = pe_vcs_send_ps_rdy_swap_run,
 	},
+	[PE_VCS_CBL_SEND_SOFT_RESET] = {
+		.entry  = pe_vcs_cbl_send_soft_reset_entry,
+		.run    = pe_vcs_cbl_send_soft_reset_run,
+	},
 #endif /* CONFIG_USBC_VCONN */
 	[PE_VDM_IDENTITY_REQUEST_CBL] = {
 		.entry  = pe_vdm_identity_request_cbl_entry,
diff --git a/include/usb_pd.h b/include/usb_pd.h
index e0f0ac0e28..f0997de7b0 100644
--- a/include/usb_pd.h
+++ b/include/usb_pd.h
@@ -956,26 +956,27 @@ enum pd_dual_role_states {
  * NOTE: These are usually set by host commands from the AP.
  */
 enum pd_dpm_request {
-	DPM_REQUEST_DR_SWAP             = BIT(0),
-	DPM_REQUEST_PR_SWAP             = BIT(1),
-	DPM_REQUEST_VCONN_SWAP          = BIT(2),
-	DPM_REQUEST_GOTO_MIN            = BIT(3),
-	DPM_REQUEST_SRC_CAP_CHANGE      = BIT(4),
-	DPM_REQUEST_GET_SNK_CAPS        = BIT(5),
-	DPM_REQUEST_SEND_PING           = BIT(6),
-	DPM_REQUEST_SOURCE_CAP          = BIT(7),
-	DPM_REQUEST_NEW_POWER_LEVEL     = BIT(8),
-	DPM_REQUEST_VDM                 = BIT(9),
-	DPM_REQUEST_BIST_TX             = BIT(10),
-	DPM_REQUEST_SNK_STARTUP         = BIT(11),
-	DPM_REQUEST_SRC_STARTUP         = BIT(12),
-	DPM_REQUEST_HARD_RESET_SEND     = BIT(13),
-	DPM_REQUEST_SOFT_RESET_SEND     = BIT(14),
-	DPM_REQUEST_PORT_DISCOVERY      = BIT(15),
-	DPM_REQUEST_SEND_ALERT          = BIT(16),
-	DPM_REQUEST_ENTER_USB           = BIT(17),
-	DPM_REQUEST_GET_SRC_CAPS        = BIT(18),
-	DPM_REQUEST_EXIT_MODES          = BIT(19),
+	DPM_REQUEST_DR_SWAP                     = BIT(0),
+	DPM_REQUEST_PR_SWAP                     = BIT(1),
+	DPM_REQUEST_VCONN_SWAP                  = BIT(2),
+	DPM_REQUEST_GOTO_MIN                    = BIT(3),
+	DPM_REQUEST_SRC_CAP_CHANGE              = BIT(4),
+	DPM_REQUEST_GET_SNK_CAPS                = BIT(5),
+	DPM_REQUEST_SEND_PING                   = BIT(6),
+	DPM_REQUEST_SOURCE_CAP                  = BIT(7),
+	DPM_REQUEST_NEW_POWER_LEVEL             = BIT(8),
+	DPM_REQUEST_VDM                         = BIT(9),
+	DPM_REQUEST_BIST_TX                     = BIT(10),
+	DPM_REQUEST_SNK_STARTUP                 = BIT(11),
+	DPM_REQUEST_SRC_STARTUP                 = BIT(12),
+	DPM_REQUEST_HARD_RESET_SEND             = BIT(13),
+	DPM_REQUEST_SOFT_RESET_SEND             = BIT(14),
+	DPM_REQUEST_PORT_DISCOVERY              = BIT(15),
+	DPM_REQUEST_SEND_ALERT                  = BIT(16),
+	DPM_REQUEST_ENTER_USB                   = BIT(17),
+	DPM_REQUEST_GET_SRC_CAPS                = BIT(18),
+	DPM_REQUEST_EXIT_MODES                  = BIT(19),
+	DPM_REQUEST_SOP_PRIME_SOFT_RESET_SEND   = BIT(20),
 };
 
 /**
diff --git a/test/usb_pe.h b/test/usb_pe.h
index 373bf9f5b2..a4967d02e5 100644
--- a/test/usb_pe.h
+++ b/test/usb_pe.h
@@ -120,6 +120,7 @@ enum usb_pe_state {
 	PE_VCS_TURN_ON_VCONN_SWAP,
 	PE_VCS_TURN_OFF_VCONN_SWAP,
 	PE_VCS_SEND_PS_RDY_SWAP,
+	PE_VCS_CBL_SEND_SOFT_RESET,
 	PE_VDM_IDENTITY_REQUEST_CBL,
 	PE_INIT_PORT_VDM_IDENTITY_REQUEST,
 	PE_INIT_VDM_SVIDS_REQUEST,
diff --git a/test/usb_pe_drp.c b/test/usb_pe_drp.c
index 10269db779..8138bb5ddf 100644
--- a/test/usb_pe_drp.c
+++ b/test/usb_pe_drp.c
@@ -189,6 +189,16 @@ test_static int test_send_caps_error_before_connected(void)
 		EC_SUCCESS, "%d");
 	mock_prl_message_sent(PORT0);
 
+	/*
+	 * Cable soft reset is always issued after entry into Src/Snk_Ready
+	 * simulate no cable response.
+	 */
+	TEST_EQ(mock_prl_wait_for_tx_msg(PORT0, TCPC_TX_SOP_PRIME,
+					 PD_CTRL_SOFT_RESET, 0,
+					 60 * MSEC),
+					 EC_SUCCESS, "%d");
+	mock_prl_report_error(PORT0, ERR_TCH_XMIT, TCPC_TX_SOP_PRIME);
+
 	TEST_EQ(finish_src_discovery(), EC_SUCCESS, "%d");
 
 	task_wait_event(5 * SECOND);
@@ -225,6 +235,16 @@ test_static int test_send_caps_error_when_connected(void)
 	mock_prl_message_sent(PORT0);
 
 	/*
+	 * Cable soft reset is always issued after entry into Src/Snk_Ready
+	 * simulate no cable response.
+	 */
+	TEST_EQ(mock_prl_wait_for_tx_msg(PORT0, TCPC_TX_SOP_PRIME,
+					 PD_CTRL_SOFT_RESET, 0,
+					 60 * MSEC),
+					 EC_SUCCESS, "%d");
+	mock_prl_report_error(PORT0, ERR_TCH_XMIT, TCPC_TX_SOP_PRIME);
+
+	/*
 	 * Expect VENDOR_DEF for cable identity, simulate no cable (so no
 	 * GoodCRC, so ERR_TCH_XMIT). Don't reply NOT_SUPPORTED, since the spec
 	 * says a cable never does that.
diff --git a/test/usb_tcpmv2_compliance_common.c b/test/usb_tcpmv2_compliance_common.c
index 92efe5a616..a5ff2348d4 100644
--- a/test/usb_tcpmv2_compliance_common.c
+++ b/test/usb_tcpmv2_compliance_common.c
@@ -320,7 +320,6 @@ int proc_pd_e1(enum pd_data_role data_role, enum proc_pd_e1_attach attach)
 						      PD_CTRL_PS_RDY, 0),
 				EC_SUCCESS, "%d");
 			mock_set_alert(TCPC_REG_ALERT_TX_SUCCESS);
-			task_wait_event(1 * MSEC);
 
 			TEST_EQ(tc_is_attached_src(PORT0), true, "%d");
 			break;
@@ -366,6 +365,14 @@ int proc_pd_e3(void)
 int handle_attach_expected_msgs(enum pd_data_role data_role)
 {
 	if (data_role == PD_ROLE_DFP) {
+		TEST_EQ(verify_tcpci_transmit(TCPC_TX_SOP_PRIME,
+				PD_CTRL_SOFT_RESET, 0),
+			EC_SUCCESS, "%d");
+		mock_set_alert(TCPC_REG_ALERT_TX_SUCCESS);
+		task_wait_event(10 * MSEC);
+		partner_send_msg(PD_MSG_SOP_PRIME, PD_CTRL_NOT_SUPPORTED, 0, 0,
+			NULL);
+
 		TEST_EQ(verify_tcpci_transmit(TCPC_TX_SOP_PRIME, 0,
 				PD_DATA_VENDOR_DEF),
 			EC_SUCCESS, "%d");