[PATCH v2] usb: typec: tcpm: advance vdm_discovery_state on Discover Identity Not_Supported

[Xu Yang]

From: Xu Yang <xu.yang_2@xxxxxxx>

Commit Fixes: 205dc9cb39f5 ("usb: typec: tcpm: implement retry mechanism
for Discover Identity VDMs") advances vdm_discovery_state to
VDM_DISCOVERY_COMPLETE when a CMDT_RSP_NAK is received, but it does not
advance the state when a non-modal port returns PD_CTRL_NOT_SUPP.

This can re-arm another vdm_discovery_work if the port is going to
respond with PD_CTRL_NOT_SUPP to the partner.

  tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
    tcpm_queue_message();
      mod_tcpm_delayed_work();
        tcpm_state_machine_work()
          tcpm_send_queued_message()  -> send PD_MSG_CTRL_NOT_SUPP
          run_state_machine()
            case SRC_READY:
            case SNK_READY:
              mod_vdm_discovery_delayed_work(port, 0);

If both the port and its partner do not support modal operation, they
will send DISCOVER_IDENTITY to each other infinitely.

Advance vdm_discovery_state to VDM_DISCOVERY_COMPLETE in this path as
well. In particular, update the state to VDM_DISCOVERY_COMPLETE if it comes
from the port partner, and to VDM_DISCOVERY_CABLE_IDENT if it comes from a
cable.

Fixes: 205dc9cb39f5 ("usb: typec: tcpm: implement retry mechanism for Discover Identity VDMs")
Signed-off-by: Xu Yang <xu.yang_2@xxxxxxx>

---
Changes in v2:
 - cover a cable returns PD_CTRL_NOT_SUPP case reported by sashiko
 - kick off vdm_discovery work to continue working
 - correct previous wrong fix commit id
---
 drivers/usb/typec/tcpm/tcpm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 2d6b14aa2085..5cea820e00c4 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3891,6 +3891,16 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
 		case SRC_READY:
 		case SNK_READY:
 			if (port->vdm_state > VDM_STATE_READY) {
+				if (port->ams == DISCOVER_IDENTITY) {
+					if (rx_sop_type == TCPC_TX_SOP) {
+						tcpm_update_vdm_discovery_state(port,
+								VDM_DISCOVERY_COMPLETE);
+					} else if (rx_sop_type == TCPC_TX_SOP_PRIME) {
+						tcpm_update_vdm_discovery_state(port,
+								VDM_DISCOVERY_CABLE_IDENT);
+						mod_vdm_discovery_delayed_work(port, 0);
+					}
+				}
 				port->vdm_state = VDM_STATE_DONE;
 				if (tcpm_vdm_ams(port))
 					tcpm_ams_finish(port);
-- 
2.34.1