On Mon, 5 Dec 2011, Vane, Edwin wrote: > 1-7 is the bus id for the hub. > > I tried using your commands (i.e. echoing to bConfigurationValue) but > it had no effect. Power/control already had 'auto' in it and > bConfigurationValue was initially 1. After echoing 0, > bConfigurationValue became empty but no change occurred on the device > so I just restored bConfigurationValue back to 1. There should have been some effect -- the device should have been suspended after a couple of seconds. Did you compare the contents of the power/runtime_status file before and after? > The only luck I've had so far is to use the hubpower command followed > by an unbind (unbind by itself doesn't do anything either). It should not be possible to do an unbind after using the hubpower program. hubpower itself already does the unbind and more. > All this > seems to do is actually just turn off the data signal. Using a > "voltmeter" (a usb connector with a LED attached) I still see power > being delivered. As was mentioned before, many hubs are not capable of turning off power to their USB ports. > Unfortunately, just turning off data doesn't seem to > satisfy this device I'm trying to work with. So my next goal is to > find a hub that supports turning off power. I found one that lsusb > reports as supporting ganged power switching but I've also read this > is no guarantee that the hub actually supports it. Correct, it isn't. > Doing more searching, I came across a linux-usb-users post that > recommended this program: > http://www.gniibe.org/development/ac-power-control-by-USB-hub/index. > I'm looking to see if it needs any modification for ganged power > switching. Right now the command-line supports only specifying one > port at a time. The program described there (hub-ctrl) does pretty much the same thing as hubpower. In fact, I originally wrote hubpower in order to have a simplified version of hub-ctrl. 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
