On 28/01/2011, at 18:28, Hans Petter Selasky wrote: > For this kind of applications ISOCHRONOUS transfers should be used. Then you > can have a double buffer guard in the range 1-56ms, regardless of the buffer > size the hardware uses.
Hmm, OK, I will have a look at changing it, although it is a bit of a pain because you can't stall an ISO EP and I'm using stall to indicate an error. Is it possible to change the amount that is buffered? This is a specialised application so a custom kernel is no problem. Even a hint in the right direction would be greatly appreciated :) > You could also try an XHCI controller, because the BULK buffering is done > differently there. OK thanks, I'll try that too. > >> I obviously don't need any more >> throughput, however my application is very sensitive to latency, as I am >> reading out of a fairly small FIFO and if it fills up my entire run has to >> be aborted. > > > > --HPS > -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"