On Thu, Nov 16, 2023 at 04:32:16PM +0800, Guan-Yu Lin wrote:
> 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@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/tcpm/tcpm.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 058d5b853b57..ff3c171a3a75 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;
> }
> --
> 2.43.0.rc0.421.g78406f8d94-goog
--
heikki
