> > Where can I measure this? > > > Two possible reasons: > > > > 1. You have not gpio control for vbus toggle when role switches. > > This works well. > > > 2. Your hardware has some problems that the vbus can't lower than 0.8v. > > How can I check that? > Just measure the voltage of your otg vbus pin. Best regards, Peter -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html