From: Peng Fan <[email protected]> After reaching SNK_READY or SRC_READY, the poll loop exits immediately. However, some PD sources send follow-up messages (e.g., Get_Sink_Cap, Get_Status) shortly after the explicit contract is established. Since the TCPCI hardware auto-sends GoodCRC for received messages, the source expects a timely response. If no response arrives within SenderResponseTimer (24-30ms), the source sends a Hard Reset, causing VBUS to drop and resetting VBUS-powered boards.
Add a 500ms settling period after reaching Ready state to process any follow-up messages from the source before entering low power mode and disabling PD message reception. Signed-off-by: Peng Fan <[email protected]> --- drivers/usb/tcpm/tcpm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/usb/tcpm/tcpm.c b/drivers/usb/tcpm/tcpm.c index 25ff0926cdf..d6af0fae7c1 100644 --- a/drivers/usb/tcpm/tcpm.c +++ b/drivers/usb/tcpm/tcpm.c @@ -2252,6 +2252,16 @@ static void tcpm_poll_event(struct udevice *dev) tcpm_check_and_run_delayed_work(dev); } + if (port->state == SNK_READY || port->state == SRC_READY) { + int settle; + + for (settle = 0; settle < 1000; settle++) { + drvops->poll_event(dev); + udelay(500); + tcpm_check_and_run_delayed_work(dev); + } + } + if (port->state != SNK_READY && port->state != SRC_READY) dev_warn(dev, "TCPM: exit in state %s\n", tcpm_states[port->state]); -- 2.51.0
