Dear Chen Peter-B29397, > > 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. Ok, I see it's 2.25 volts after I disconnect the microB-A thing . I should see 0.8V constantly with nothing connected on the port? Best regards, Marek Vasut -- 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
