On Sun, 18 Sep 2011, Lenny Story wrote: > Greetings, > > I am using a custom composite usb device with a known hub. It has per > port power control, and when turned off i can confirm that the power > is indeed off (via volt measurement). However, doing a followup > "lsusb" the device still shows in the list. When i try to read the > detailed descriptors, the device reports a timeout, although it still > remains in lsusb list. > > Is there some API i am missing to get khubd to pickup the change ? No. The kernel's USB stack expects that only the hub driver will communicate with hubs. If you go behind the hub driver's back to turn off power to some ports, the results are unspecified. > I am using Libusb1.0 sending direct setFeature requests to the HUB. > > Thoughts anyone ? You should unbind the hub from the hub driver before messing with its ports. Use libusb_detach_kernel_driver(). 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
