Oliver Neukum napsal(a):
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.
You are _that_ guy, who reviewed the code. So you should be better
informed. The latest version is at
[http://dave.ok.cz/cdc-acm_release/linux-2.6.12-rc5_stable-cdc-acm.patch].
It should run in 2.6.12-rc5 but I'm not sure, I have not yet test this
version. I can ask the author what's the current status.
--Petr
-------------------------------------------------------
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
