On Friday 25 October 2002 07:17 pm, David Brownell wrote: > anton wilson wrote: > > In a USB driver, I'm chaining ISO urbs by resubmitting the URBS in the > > completion handler. I also time the calls to the urb completion handlers > > using do_gettimeofday(). Most of the time, the time between interrupts is > > at most 1.01 ms, but occasionally there may be a 2 ms time inbetween > > interrupts. > > Quite reasonable ... even expected, if something else (BIOS intrusion?) > blocks out IRQs for no more than a millisecond or so. If interrupts are > blocked for longer times, or other stuff kicks in, it could be longer. > > Are you just chaining, or is another URB queued to handle I/O delays? > Most folk seem to arrange a handful of packets per URB, and keep two urbs > queued, which tends to tie down about two pages per ISO stream and cost a > couple hundred IRQs per second (full speed).
I'm just chaining. 4 urbs per device. 2 read urbs and 2 write urbs. I'm testing with 3 devices. Are you saying that my delays may be caused by memory accesses? Thanks, Anton > > - Dave > > > > > ------------------------------------------------------- > This sf.net email is sponsored by: Influence the future > of Java(TM) technology. Join the Java Community > Process(SM) (JCP(SM)) program now. > http://ads.sourceforge.net/cgi-bin/redirect.pl?sunm0004en > _______________________________________________ > [EMAIL PROTECTED] > To unsubscribe, use the last form field at: > https://lists.sourceforge.net/lists/listinfo/linux-usb-devel ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
