On Tue, 11 Nov 2003, Ian R. Meinzen wrote: > Alan Stern wrote: > > 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 > > > Sorry, I should have put at least that in. I'm running 2.4.22 with the > usb-uhci driver. Should I get a -ENXIO on the first urb submitted, > though? I don't submit any urbs before a read/write/ioctl, and I am > getting an error on the first read, when the urb is first submitted. The > device returns an interrupt urb when it receives the the control urb. > Does the receipt urb need to be submitted BEFORE the control urb?
You shouldn't have problems with the first URB submitted. You don't have to submit the receipt URB before the control URB. Just be sure that you are sending each URB to the correct endpoint and not both to the same endpoint by mistake. My original advice still stands. Edit the usb-uhci.c source file and get rid of the part where it redefines DEBUG and dbg to do nothing. Running with debugging turned on will give you plenty of useful information. 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
