On Mon, 20 Apr 2015, Dave Mielke wrote: > It seems (from inspecting libusb) that poll()ing a usbfs file descriptor for > output can be used to determine when a urb can be reaped. A user has sent me a > patch to our code that does this, and it actually does seem to work. So far, I > haven't found any documentation on this. > > Is it okay for us to use this capability? Yes, it's okay. A userspace ABI like that isn't going to go away. It's also true that you can poll for POLLERR or POLLHUP to see when a device has been disconnected, although libusb probably isn't interested in doing that. > Can anyone point me to documentation that formally describes how it works? As far as I can see, there isn't any documentation for usbfs at all apart from Documentation/usb/proc_usb_info.txt, which is woefully out of date. 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
