Am Dienstag, 30. August 2005 21:35 schrieb Petr Pisar: > Greg Lee napsal(a): > >>>Currently I've made a preliminary firmware for implementing the > >>>CDC-ACM interface, however as Pavel kindly pointed out for me, > >>>currently only 64Kbyte/sec is achieveable with this driver. I've read > >>>the archives and from the discussions, I suspect that this is > >>>connected to the NO_FSBR flag.. > >>> > >>>Questions which popped out of my mind: > >>>1. Is there some standard way to allow for >64Kbytes/sec using the > >>>2.6.x CDC-ACM driver? (I mean without modification of the sources, but > >>>setting some #defines or such) I'd not mind a reasonably slower PCI > >>>bus.. > >> > >>I don't know. I've never heard about a 64 KB/s limitation > >>for CDC-ACM. > > > > > > This discussion of possible underlying data rate limitations in the CDC-ACM > > implementation is worrisome. Does anyone have a precise answer for what the > > data rate limitations are of these two implementations (usbserial and ACM)? > > I've made a switch from embedded OS to Linux recently in order to take > > advantage of Linux's native USB support and am wondering whether this was > > the wrong move. > > > > I'd be interested in whatever people have to say about this. > > > > I have reported in this conference yet ("usbserial driver throughput low" > form Wed, 15 Jun 2005 22:01:07 -0400) that one guy from Czech Rep. had > rewritten cdc-acm. He uses 3 kernel threads and buffers to eliminate packet > fragmentation and jitter. I don't know if is ported to the 2.6.13, but in > those days on 2.6.11 kernel it worked fine.
Do you happen to have an URL? I'd like to include it in 2.6.14. Regards Oliver ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel