On Wed, 14 May 2014, Grant wrote: > >> Can I disable VBUS while keeping the rest of USB functional for a > >> device that does not require bus power? > > > > unfortunately not, your device would see a disconnection. The reason is > > that even though you don't really put any load on the bus, the PHY still > > samples VBUS levels to know when the session is valid (VBUS > 4.4V). > > > Darn. My goals are to minimize power usage and the amount of > electrical noise traveling to my USB device so I was hoping to > eliminate the otherwise unused VBUS. Any creative ways to pull this > off? The simplest solution is to unplug your device when you're not using it. :-) Also, bear in mind that many hubs and host controllers are not capable of turning off Vbus. Alan Stern -- 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
