From: Guan-Yu Lin <guanyulin@google.com>
Date: Thu, 16 Nov 2023 08:32:16 +0000 (+0800)
Subject: usb: typec: tcpm: skip checking port->send_discover in PD3.0
X-Git-Tag: v6.8-rc1~58^2~142
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0cc05d52ad310cced029449bcda0f9fc847097c;p=thirdparty%2Fkernel%2Flinux.git

usb: typec: tcpm: skip checking port->send_discover in PD3.0

The original Collison Avoidance mechanism, port->send_discover, avoids
the conflict when port partners start AMS almost the same time. However,
this mechanism is replaced by SINK_TX_OK and SINK_TX_NG. Skip the check
in PD3.0 to avoid the deadlock when source is requesting DR_SWAP where
sink is requesting DISCOVER_IDENTITY.

Signed-off-by: Guan-Yu Lin <guanyulin@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231116083221.1201892-1-guanyulin@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 058d5b853b574..ff3c171a3a75e 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -2847,7 +2847,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 					   PD_MSG_CTRL_NOT_SUPP,
 					   NONE_AMS);
 		} else {
-			if (port->send_discover) {
+			if (port->send_discover && port->negotiated_rev < PD_REV30) {
 				tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
 				break;
 			}
@@ -2863,7 +2863,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 					   PD_MSG_CTRL_NOT_SUPP,
 					   NONE_AMS);
 		} else {
-			if (port->send_discover) {
+			if (port->send_discover && port->negotiated_rev < PD_REV30) {
 				tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
 				break;
 			}
@@ -2872,7 +2872,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 		}
 		break;
 	case PD_CTRL_VCONN_SWAP:
-		if (port->send_discover) {
+		if (port->send_discover && port->negotiated_rev < PD_REV30) {
 			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
 			break;
 		}