TCPMv2: Avoid VCONN-Source discovery failure

Remove redundant checks for VCONN Source in pe_attempt_port_discovery
(which prevent discovery from running). Allow pe_vdm_send_request to
attempt to become VCONN Source if necessary. Make the checks in the VDM
request child states more complete (not just checking for VCONN Source).

BUG=b:170662791
TEST=Attach Tapex Creek board; observed successful discovery
BRANCH=none

Signed-off-by: Abe Levkoy <alevkoy@chromium.org>
Change-Id: Id7d3a1b82d1029f69b3e05b845632e7237524bc6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2486303
Tested-by: Li1 Feng <li1.feng@intel.com>
Reviewed-by: Diana Z <dzigterman@chromium.org>

4 files changed, 27 insertions, 10 deletions

diff --git a/common/mock/usb_tc_sm_mock.c b/common/mock/usb_tc_sm_mock.c
index dfe8eeef48..7679cae260 100644
--- a/common/mock/usb_tc_sm_mock.c
+++ b/common/mock/usb_tc_sm_mock.c
@@ -30,6 +30,7 @@ void mock_tc_port_reset(void)
 		mock_tc_port[port].lcl_rp = TYPEC_RP_RESERVED;
 		mock_tc_port[port].attached_snk = 0;
 		mock_tc_port[port].attached_src = 0;
+		mock_tc_port[port].vconn_src = false;
 	}
 }
 
@@ -85,7 +86,7 @@ void tc_ctvpd_detected(int port)
 
 int tc_is_vconn_src(int port)
 {
-	return 0;
+	return mock_tc_port[port].vconn_src;
 }
 
 void tc_hard_reset_request(int port)
diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index e599097f43..655bae4599 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -1580,7 +1580,7 @@ static bool pe_attempt_port_discovery(int port)
 	 */
 	if (get_time().val > pe[port].discover_identity_timer) {
 		if (pd_get_identity_discovery(port, TCPC_TX_SOP_PRIME) ==
-				PD_DISC_NEEDED && pe_can_send_sop_prime(port)) {
+				PD_DISC_NEEDED) {
 			pe[port].tx_type = TCPC_TX_SOP_PRIME;
 			set_state_pe(port, PE_VDM_IDENTITY_REQUEST_CBL);
 			return true;
@@ -1604,14 +1604,12 @@ static bool pe_attempt_port_discovery(int port)
 			set_state_pe(port, PE_INIT_VDM_MODES_REQUEST);
 			return true;
 		} else if (pd_get_svids_discovery(port, TCPC_TX_SOP_PRIME)
-				== PD_DISC_NEEDED &&
-				pe_can_send_sop_prime(port)) {
+				== PD_DISC_NEEDED) {
 			pe[port].tx_type = TCPC_TX_SOP_PRIME;
 			set_state_pe(port, PE_INIT_VDM_SVIDS_REQUEST);
 			return true;
 		} else if (pd_get_modes_discovery(port, TCPC_TX_SOP_PRIME) ==
-				PD_DISC_NEEDED &&
-				pe_can_send_sop_prime(port)) {
+				PD_DISC_NEEDED) {
 			pe[port].tx_type = TCPC_TX_SOP_PRIME;
 			set_state_pe(port, PE_INIT_VDM_MODES_REQUEST);
 			return true;
@@ -4767,7 +4765,11 @@ static void pe_vdm_identity_request_cbl_entry(int port)
 
 	print_current_state(port);
 
-	if (!tc_is_vconn_src(port)) {
+	if (!pe_can_send_sop_prime(port)) {
+		/*
+		 * The parent state already tried to enable SOP' traffic. If it
+		 * is still disabled, there's nothing left to try.
+		 */
 		pd_set_identity_discovery(port, pe[port].tx_type, PD_DISC_FAIL);
 		set_state_pe(port, get_last_state_pe(port));
 		return;
@@ -5035,7 +5037,11 @@ static void pe_init_vdm_svids_request_entry(int port)
 	print_current_state(port);
 
 	if (pe[port].tx_type == TCPC_TX_SOP_PRIME &&
-	    !tc_is_vconn_src(port)) {
+	    !pe_can_send_sop_prime(port)) {
+		/*
+		 * The parent state already tried to enable SOP' traffic. If it
+		 * is still disabled, there's nothing left to try.
+		 */
 		pd_set_svids_discovery(port, pe[port].tx_type, PD_DISC_FAIL);
 		set_state_pe(port, get_last_state_pe(port));
 		return;
@@ -5133,7 +5139,11 @@ static void pe_init_vdm_modes_request_entry(int port)
 	print_current_state(port);
 
 	if (pe[port].tx_type == TCPC_TX_SOP_PRIME &&
-	    !tc_is_vconn_src(port)) {
+	    !pe_can_send_sop_prime(port)) {
+		/*
+		 * The parent state already tried to enable SOP' traffic. If it
+		 * is still disabled, there's nothing left to try.
+		 */
 		pd_set_modes_discovery(port, pe[port].tx_type, svid,
 				PD_DISC_FAIL);
 		set_state_pe(port, get_last_state_pe(port));
@@ -5230,7 +5240,11 @@ static void pe_vdm_request_dpm_entry(int port)
 
 	if ((pe[port].tx_type == TCPC_TX_SOP_PRIME ||
 	     pe[port].tx_type == TCPC_TX_SOP_PRIME_PRIME) &&
-	     !tc_is_vconn_src(port)) {
+	     !pe_can_send_sop_prime(port)) {
+		/*
+		 * The parent state already tried to enable SOP' traffic. If it
+		 * is still disabled, there's nothing left to try.
+		 */
 		dpm_vdm_naked(port, pe[port].tx_type,
 			      PD_VDO_VID(pe[port].vdm_data[0]),
 			      PD_VDO_CMD(pe[port].vdm_data[0]));
diff --git a/include/mock/usb_tc_sm_mock.h b/include/mock/usb_tc_sm_mock.h
index beefa40c74..f5c599ca1f 100644
--- a/include/mock/usb_tc_sm_mock.h
+++ b/include/mock/usb_tc_sm_mock.h
@@ -19,6 +19,7 @@ struct mock_tc_port_t {
 	enum tcpc_rp_value lcl_rp;
 	int attached_snk;
 	int attached_src;
+	bool vconn_src;
 };
 
 extern struct mock_tc_port_t mock_tc_port[CONFIG_USB_PD_PORT_MAX_COUNT];
diff --git a/test/usb_pe_drp.c b/test/usb_pe_drp.c
index 8c59dcf180..f780834612 100644
--- a/test/usb_pe_drp.c
+++ b/test/usb_pe_drp.c
@@ -54,6 +54,7 @@ test_static int test_send_caps_error(void)
 	/* Enable PE as source, expect SOURCE_CAP. */
 	mock_pd_port[PORT0].power_role = PD_ROLE_SOURCE;
 	mock_tc_port[PORT0].pd_enable = 1;
+	mock_tc_port[PORT0].vconn_src = true;
 	task_wait_event(10 * MSEC);
 	TEST_EQ(fake_prl_get_last_sent_data_msg_type(PORT0),
 		PD_DATA_SOURCE_CAP, "%d");