On Mon, Oct 28, 2002, anton wilson <[EMAIL PROTECTED]> wrote: > On Monday 28 October 2002 04:14 pm, Johannes Erdfelt wrote: > > On Mon, Oct 28, 2002, anton wilson <[EMAIL PROTECTED]> wrote: > > > the usb-uhci module v1.275 ... > > > I'd say 4 per device. 2 read and 2 write > > > I'm not quite sure if enqueuing all 4 at once is necessary to achieve > > > sends and recieves every ms. That's how the driver was before it was > > > handed to me... The urbs are re-submitted in the completion handler. > > > 3 devices are being used right now. > > > > That's probably not enough. There is no guarantee that the callback will > > happen quickly enough that you can reschedule it for frame afterwards. > > So right now, I submit 2 urbs for writes in the beginning and then they > resubmit themselves. If that's not enough, is there some particular quantity > that is generally enough to have 1 completion callback per millisecond? Does > the number vary according to the hardware or the HC?
The number which doesn't reproduce the problem is the number you need to use. Is latency of particular concern? If not, use something like 8 or 16 frames per URB. If so, use something like 8 or 16 URBs. JE ------------------------------------------------------- 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
