On Wed, 26 Jun 2002, Duncan Sands wrote:
>This always gives "status bits 00440000". That is "stalled" and "CRC/Time Out Error". Just guessing, but how long is your USB cable? Have you tried a different cable? >PPS: The user space driver submits on average 3 urbs per jiffy, >which is about 1 every 3 milliseconds, which is ok since I am told >the USB 1.1 spec states you shouldn't poll an interrupt endpoint faster >than 1 poll per millisec. That's misleading, since the rate at which you submit URBs has absolutely nothing to do with the Host Controller's poll rate. If you are using Bulk, then the HC is polling the device very fast, probably more than 25 times per frame (millisec). It's just that the device keeps NAKing so you don't see it (until the device ACKs). You need a bus tracer to see the real polling rate. Use USB_NO_FSBR to reduce polling to 1 per millisec (it works for me, at least, on a per-URB basis). As far as the rate of URB submission, I don't think it matters, as the HCD manages the real polling rate and is not affected by URB submission rate. -- Dan Streetman [EMAIL PROTECTED] -------------------------------------------------- 186,282 miles per second: It isn't just a good idea, it's the law! ------------------------------------------------------- Sponsored by: ThinkGeek at http://www.ThinkGeek.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
