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


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