Thanks for the response. You're absolutely right in that I muddied up what I was asking.
My issue is that I have a USB ethernet device that is incredibly chatty on a simple embedded USB chip. Every frame causes an interrupt, and thus I end up with 9000-16000 interrupts per second which degrades the system performance drastically. Initially, I tried to change the interval via the usb_fill_int_urb function, but they gave me no reductions in the amount of interrupts I was seeing in the host controller's interrupt routine. So I figured this wasn't working, which lead me to the endpoint discussion. Right now, it seems there is no way around the problem at hand and thus will have to deal with a ton of interrupts. Thanks, Adam --- Alan Stern <[EMAIL PROTECTED]> wrote: > On Thu, 28 Apr 2005, Adam Oldham wrote: > > > So in essense, there is no way to change the poll > > interval for devices outside of getting the vendor > to > > change the software on the device itself? > > Resubmitting the URB like someone else suggested > > doesn't have any affect, that I can tell. > > You need to be more careful in your choice of words > because, whether you > realize it or not, you've been asking two different > questions: > > 1. How can the bInterval value stored in the > endpoint > descriptor on the device be changed? > > 2. How can the polling interval be changed? > > The answer to 1 is, as you surmised, to get the > vendor to change the > device's firmware. > > The answer to 2 is completely different. As David > Brownell wrote, the > actual polling interval gets assigned at the time a > driver submits an URB. > You can tell the host controller driver to use any > interval you want; you > don't have to use the value that's in the > descriptor. Just pass your > value to the usb_fill_int_urb routine. > > Alan Stern > > /************************************************************ * Adam Oldham, Software Engineer, Gilbarco Inc * Greensboro, NC * Big H Performance Rally Team - http://www.bighracing.com *************************************************************/ Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html ------------------------------------------------------- This SF.Net email is sponsored by Oracle Space Sweepstakes Want to be the first software developer in space? Enter now for the Oracle Space Sweepstakes! http://ads.osdn.com/?ad_id=7393&alloc_id=16281&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
