TCPMv2: PRL: Don't report ERR_RCH_CHUNKED to PE for timeout

This CL adds a new RCH error type used for the case when there was a
sender response timeout waiting for the next chunk of a chunked
message to be received. This particular error should not result in the
PE triggering a soft reset. This new error type allows the PE function
to do nothing for this error case. All other RCH error states remain
the same.

This change is required to pass the TD.PD.SRC3.E32 compliance test
where the tester purposely stops sending after the 4th chunk and
expects to be able to resend that message without an protocol error
being reported.

BUG=b:181333342,b:179443762
BRANCH=None
TEST=Verified that quiche can now pass  TD.PD.SRC3.E32

Signed-off-by: Scott Collyer <scollyer@google.com>
Change-Id: I0142ca8d23cd23ef7b347d5c07155cdb17f44b88
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2734158
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Tested-by: Denis Brockus <dbrockus@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Commit-Queue: Scott Collyer <scollyer@chromium.org>

2 files changed, 21 insertions, 4 deletions

diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c
index 4e9d1b2c44..e3c3ee4627 100644
--- a/common/usbc/usb_pe_drp_sm.c
+++ b/common/usbc/usb_pe_drp_sm.c
@@ -1126,6 +1126,13 @@ void pe_report_error(int port, enum pe_error e, enum tcpm_transmit_type type)
 	assert(port == TASK_ID_TO_PD_PORT(task_get_current()));
 
 	/*
+	 * If there is a timeout error while waiting for a chunk of a chunked
+	 * message, there is no requirement to trigger a soft reset.
+	 */
+	if (e == ERR_RCH_CHUNK_WAIT_TIMEOUT)
+		return;
+
+	/*
 	 * Generate Hard Reset if Protocol Error occurred
 	 * while in PE_Send_Soft_Reset state.
 	 */
diff --git a/common/usbc/usb_prl_sm.c b/common/usbc/usb_prl_sm.c
index 91bb54746a..34f0ff251d 100644
--- a/common/usbc/usb_prl_sm.c
+++ b/common/usbc/usb_prl_sm.c
@@ -296,6 +296,8 @@ static struct rx_chunked {
 	struct sm_ctx ctx;
 	/* PRL_FLAGS */
 	uint32_t flags;
+	/* error to report when moving to rch_report_error state */
+	enum pe_error error;
 } rch[CONFIG_USB_PD_PORT_MAX_COUNT];
 
 /* Chunked Tx State Machine Object */
@@ -1494,6 +1496,7 @@ static void rch_wait_for_message_from_protocol_layer_run(const int port)
 			 * Chunked != Chunking
 			 */
 			else {
+				rch[port].error = ERR_RCH_CHUNKED;
 				set_state_rch(port, RCH_REPORT_ERROR);
 			}
 		}
@@ -1510,6 +1513,7 @@ static void rch_wait_for_message_from_protocol_layer_run(const int port)
 		 * revision lower than PD3.0
 		 */
 		else {
+			rch[port].error = ERR_RCH_CHUNKED;
 			set_state_rch(port, RCH_REPORT_ERROR);
 		}
 	}
@@ -1563,6 +1567,7 @@ static void rch_processing_extended_message_run(const int port)
 		/* Make sure extended message buffer does not overflow */
 		if (pdmsg[port].num_bytes_received +
 					byte_num > EXTENDED_BUFFER_SIZE) {
+			rch[port].error = ERR_RCH_CHUNKED;
 			set_state_rch(port, RCH_REPORT_ERROR);
 			return;
 		}
@@ -1593,8 +1598,10 @@ static void rch_processing_extended_message_run(const int port)
 	/*
 	 * Unexpected Chunk Number
 	 */
-	else
+	else {
+		rch[port].error = ERR_RCH_CHUNKED;
 		set_state_rch(port, RCH_REPORT_ERROR);
+	}
 }
 
 /*
@@ -1630,6 +1637,7 @@ static void rch_requesting_chunk_run(const int port)
 		set_state_rch(port, RCH_WAITING_CHUNK);
 	} else if (PDMSG_CHK_FLAG(port, PRL_FLAGS_TX_ERROR)) {
 		/* Transmission Error from Protocol Layer detetected */
+		rch[port].error = ERR_RCH_CHUNKED;
 		set_state_rch(port, RCH_REPORT_ERROR);
 	} else if (RCH_CHK_FLAG(port, PRL_FLAGS_MSG_RECEIVED)) {
 		/*
@@ -1685,6 +1693,7 @@ static void rch_waiting_chunk_run(const int port)
 			 */
 			if (PD_EXT_HEADER_REQ_CHUNK(exhdr) ||
 			    !PD_EXT_HEADER_CHUNKED(exhdr)) {
+				rch[port].error = ERR_RCH_CHUNKED;
 				set_state_rch(port, RCH_REPORT_ERROR);
 			}
 			/*
@@ -1704,8 +1713,10 @@ static void rch_waiting_chunk_run(const int port)
 	/*
 	 * ChunkSenderResponseTimer Timeout
 	 */
-	else if (pd_timer_is_expired(port, PR_TIMER_CHUNK_SENDER_RESPONSE))
+	else if (pd_timer_is_expired(port, PR_TIMER_CHUNK_SENDER_RESPONSE)) {
+		rch[port].error = ERR_RCH_CHUNK_WAIT_TIMEOUT;
 		set_state_rch(port, RCH_REPORT_ERROR);
+	}
 }
 
 static void rch_waiting_chunk_exit(int port)
@@ -1734,8 +1745,7 @@ static void rch_report_error_entry(const int port)
 		/* Report error */
 		pe_report_error(port, ERR_RCH_MSG_REC, prl_rx[port].sop);
 	} else {
-		/* Report error */
-		pe_report_error(port, ERR_RCH_CHUNKED, prl_rx[port].sop);
+		pe_report_error(port, rch[port].error, prl_rx[port].sop);
 	}
 }