On Tue, 11 Nov 2003, Ian R. Meinzen wrote: > Hello all, > First, a disclaimer - I am very new to driver development, so please > bear with my ignorance. > > I am trying to write a device driver for a USB U401 from usbmicro.com. > The device works by sending a control packet to the device, then > receiving an interrupt packet back. I have (I think) the send portion > down pat, but I have yet to get the response URB correctly. I am trying > to receive the URB by calling usb_fill_int_urb() and then > usb_submit_urb() on the URB. I receive a -ENXIO from usb_submit_urb(), > and the urb->status found in the callback function is -ENOPIPE. I'm not > real sure what additional info I need to send, so please tell me if I > need to give more info.
You didn't say what version of Linux you're running or which host controller driver -- my guess is 2.4.x and one of the UHCI drivers. They return -ENXIO when you try to submit two URBs for the same interrupt endpoint. (Note: when usb_submit_urb() returns an error code, urb->status is meaningless.) If that's what you're doing, it shouldn't be a problem to delay submitting each URB until after the previous one has completed. If you want to see more information, edit the source file for your HCD to leave DEBUG and dbg defined. Alan Stern ------------------------------------------------------- This SF.Net email sponsored by: ApacheCon 2003, 16-19 November in Las Vegas. Learn firsthand the latest developments in Apache, PHP, Perl, XML, Java, MySQL, WebDAV, and more! http://www.apachecon.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
