On Fri, Jan 07, 2005 at 10:35:16AM -0800, [EMAIL PROTECTED] wrote: > I am seeing maximum throughput of a little over 400kbits/second using > an Airprime PC5220 card and the generic usb serial driver. A windows driver > can get over twice the throughput.
Good for it :) > Throughput to me being TCP throughput after I have started up pppd on the > ttyUSB0 port. > > I noticed a comment from you on one of the mailing lists suggesting that > the generic USB driver is not optimized for speed and suggests that I should > take a look at the empeg driver for an example of a driver with higher > throughput. > > The empeg driver seems to do basically the same thing inside the > bulk_read_callback that the generic driver does. It just pops the bytes into > the flip buffer and resubmits the urb. Yes, it uses multiple write urbs, not multiple read urbs. > I looked in the ir-usb driver which can use multiple urbs, but it looks like > this happens when the particular port offers multiple endpoints. > > I highly suspect that the problem is on the incoming side, (as the only data > flowing the other way are the TCP ACKs). Can you give me some insight into > where I should look for solutions to my problem? Any hints or pointers to > resources will be appreciated. Especially any ideas as to where you think the > bottleneck might be. > > I saw (either on a list or in one of your L.J. articles) that it is possible > to use a pool of urbs for one endpoint. Is this true for a bulk read endpoint? Yup. > Is there an example floating around? Not that I know of, sorry. If you want a fast driver for your device, don't use the generic one, you will have to write a custom one, sorry. thanks, greg k-h ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
