usb: typec: tcpm: Do not finish VDM AMS for retrying Responses

If the VDM responses couldn't be sent successfully, it doesn't need to
finish the AMS until the retry count reaches the limit.

Fixes: 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210606081452.764032-1-kyletso@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 a7c336f..63470cf 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -1942,6 +1942,9 @@ static void vdm_run_state_machine(struct tcpm_port *port)
                        tcpm_log(port, "VDM Tx error, retry");
                        port->vdm_retries++;
                        port->vdm_state = VDM_STATE_READY;
+                       if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMDT(vdo_hdr) == CMDT_INIT)
+                               tcpm_ams_finish(port);
+               } else {
                        tcpm_ams_finish(port);
                }
                break;