usb-pd: send more request after wait

When we are not in an explicit contract, we still need to send more
requests attempts when we receive a WAIT control command. Otherwise,
the port partner can issue a hard reset.

BRANCH=none
BUG=b:117498337
TEST=hard reset boot loop goes away with this CL.

Change-Id: Iabe8f086659dc0d7a405fa9f17495fb1c61494cc
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1289311
Commit-Ready: Edward Hill <ecgh@chromium.org>
Reviewed-by: Edward Hill <ecgh@chromium.org>

2 files changed, 120 insertions, 37 deletions

diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index e9e86be32b..988443aba1 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -1381,6 +1381,7 @@ static void handle_data_request(int port, uint16_t head,
 	case PD_DATA_SOURCE_CAP:
 		if ((pd[port].task_state == PD_STATE_SNK_DISCOVERY)
 			|| (pd[port].task_state == PD_STATE_SNK_TRANSITION)
+			|| (pd[port].task_state == PD_STATE_SNK_REQUESTED)
 #ifdef CONFIG_USB_PD_VBUS_DETECT_NONE
 			|| (pd[port].task_state ==
 			    PD_STATE_SNK_HARD_RESET_RECOVER)
@@ -1650,49 +1651,46 @@ static void handle_ctrl_request(int port, uint16_t head,
 			set_state(port, PD_STATE_SNK_READY);
 		else if (pd[port].task_state == PD_STATE_SNK_REQUESTED) {
 			/*
-			 * Explicit Contract in place
+			 * On reception of a WAIT message, transition to
+			 * PD_STATE_SNK_READY after PD_T_SINK_REQUEST ms to
+			 * send another request.
 			 *
-			 *  On reception of a WAIT message, transition to
-			 *  PD_STATE_SNK_READY after PD_T_SINK_REQUEST ms to
-			 *  send another reqest.
+			 * On reception of a REJECT message, transition to
+			 * PD_STATE_SNK_READY but don't resend the request if
+			 * we already have a contract in place.
 			 *
-			 *  On reception of a REJECT messag, transition to
-			 *  PD_STATE_SNK_READY but don't resend the request.
-			 *
-			 * NO Explicit Contract in place
-			 *
-			 *  On reception of a WAIT or REJECT message,
-			 *  transition to PD_STATE_SNK_DISCOVERY
+			 * On reception of a REJECT message without a contract,
+			 * transition to PD_STATE_SNK_DISCOVERY instead.
 			 */
-			if (pd[port].flags & PD_FLAGS_EXPLICIT_CONTRACT) {
-				/* We have an explicit contract */
-				if (type == PD_CTRL_WAIT) {
-					/*
-					 * Trigger a new power request when
-					 * we enter PD_STATE_SNK_READY
-					 */
-					pd[port].new_power_request = 1;
+			if (type == PD_CTRL_WAIT) {
+				/*
+				 * Trigger a new power request when
+				 * we enter PD_STATE_SNK_READY
+				 */
+				pd[port].new_power_request = 1;
 
-					/*
-					 * After the request is triggered,
-					 * make sure the request is sent.
-					 */
-					pd[port].prev_request_mv = 0;
+				/*
+				 * After the request is triggered,
+				 * make sure the request is sent.
+				 */
+				pd[port].prev_request_mv = 0;
 
-					/*
-					 * Transition to PD_STATE_SNK_READY
-					 * after PD_T_SINK_REQUEST ms.
-					 */
-					set_state_timeout(port, get_time().val +
-							PD_T_SINK_REQUEST,
-							PD_STATE_SNK_READY);
-				} else {
-					/* The request was rejected */
-					set_state(port, PD_STATE_SNK_READY);
-				}
+				/*
+				 * Transition to PD_STATE_SNK_READY
+				 * after PD_T_SINK_REQUEST ms.
+				 */
+				set_state_timeout(port,
+						  get_time().val +
+							  PD_T_SINK_REQUEST,
+						  PD_STATE_SNK_READY);
 			} else {
-				/* No explicit contract */
-				set_state(port, PD_STATE_SNK_DISCOVERY);
+				/* The request was rejected */
+				const int in_contract =
+					pd[port].flags &
+					PD_FLAGS_EXPLICIT_CONTRACT;
+				set_state(port,
+					  in_contract ? PD_STATE_SNK_READY
+						      : PD_STATE_SNK_DISCOVERY);
 			}
 		}
 #endif
diff --git a/test/usb_pd.c b/test/usb_pd.c
index 1d8f91f8d8..9365983b35 100644
--- a/test/usb_pd.c
+++ b/test/usb_pd.c
@@ -647,6 +647,90 @@ static int test_request_with_wait(void)
 	return EC_SUCCESS;
 }
 
+static int test_request_with_wait_no_src_cap(void)
+{
+#ifdef CONFIG_USB_PD_GIVE_BACK
+	uint32_t expected_rdo = RDO_FIXED(1, 900, PD_MIN_CURRENT_MA,
+					RDO_CAP_MISMATCH | RDO_GIVE_BACK);
+#else
+	uint32_t expected_rdo = RDO_FIXED(1, 900, 900, RDO_CAP_MISMATCH);
+#endif
+	uint8_t port = PORT0;
+
+	plug_in_source(port, 0);
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(2 * PD_T_CC_DEBOUNCE + 100 * MSEC);
+	TEST_ASSERT(pd_port[port].polarity == 0);
+
+	/* We're in SNK_DISCOVERY now. Let's send the source cap. */
+	simulate_source_cap(port, 0);
+	task_wait_event(30 * MSEC);
+	TEST_ASSERT(verify_goodcrc(port,
+			PD_ROLE_SINK, pd_port[port].msg_rx_id));
+
+	/* Wait for the power request */
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(35 * MSEC); /* tSenderResponse: 24~30 ms */
+	inc_rx_id(port);
+
+	/* Process the request */
+	TEST_ASSERT(pd_test_tx_msg_verify_sop(port));
+	TEST_ASSERT(pd_test_tx_msg_verify_short(port,
+			PD_HEADER(PD_DATA_REQUEST, PD_ROLE_SINK, PD_ROLE_UFP,
+			pd_port[port].msg_tx_id, 1, pd_port[port].rev, 0)));
+	TEST_ASSERT(pd_test_tx_msg_verify_word(port, expected_rdo));
+	TEST_ASSERT(pd_test_tx_msg_verify_crc(port));
+	TEST_ASSERT(pd_test_tx_msg_verify_eop(port));
+
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(30 * MSEC);
+
+	/* Request is good. Send GoodCRC */
+	simulate_goodcrc(port, PD_ROLE_SOURCE, pd_port[port].msg_tx_id);
+	task_wake(PD_PORT_TO_TASK_ID(0));
+	task_wait_event(30 * MSEC);
+	inc_tx_id(port);
+
+	/* We're in SNK_REQUESTED. Send wait */
+	simulate_wait(port);
+	task_wait_event(30 * MSEC);
+	TEST_ASSERT(verify_goodcrc(0, PD_ROLE_SINK, pd_port[port].msg_rx_id));
+
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(30 * MSEC);
+	inc_rx_id(port);
+
+	/*
+	 * Some port partners do not send another SRC_CAP and expect us to send
+	 * another REQUEST 100ms after the WAIT.
+	 */
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(100 * MSEC); /* tSinkRequest: 100 ms */
+	inc_rx_id(port);
+
+	/* Process the request */
+	TEST_ASSERT(pd_test_tx_msg_verify_sop(port));
+	TEST_ASSERT(pd_test_tx_msg_verify_short(port,
+			PD_HEADER(PD_DATA_REQUEST, PD_ROLE_SINK, PD_ROLE_UFP,
+			pd_port[port].msg_tx_id, 1, pd_port[port].rev, 0)));
+	TEST_ASSERT(pd_test_tx_msg_verify_word(port, expected_rdo));
+	TEST_ASSERT(pd_test_tx_msg_verify_crc(port));
+	TEST_ASSERT(pd_test_tx_msg_verify_eop(port));
+
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(30 * MSEC);
+
+	/* Request was good. Send GoodCRC */
+	simulate_goodcrc(port, PD_ROLE_SOURCE, pd_port[port].msg_tx_id);
+	task_wake(PD_PORT_TO_TASK_ID(port));
+	task_wait_event(30 * MSEC);
+	inc_tx_id(port);
+
+	/* We're done */
+	unplug(port);
+	return EC_SUCCESS;
+}
+
 static int test_request_with_reject(void)
 {
 #ifdef CONFIG_USB_PD_GIVE_BACK
@@ -825,6 +909,7 @@ void run_test(void)
 	RUN_TEST(test_request);
 	RUN_TEST(test_sink);
 	RUN_TEST(test_request_with_wait);
+	RUN_TEST(test_request_with_wait_no_src_cap);
 	RUN_TEST(test_request_with_wait_and_contract);
 	RUN_TEST(test_request_with_reject);