I'm still working on this ethernet driver for a USB ADSL modem. Its going pretty good, it works for the most part. I followed the model used by most other drivers, with one read URB for incoming data. I set the size of this urb's transfer_buffer to 3392, which is 64*53 - the least common multiple of a USB transfer (64 bytes) and an ATM cell (53 bytes). We do this on the Windows and Macintosh platforms as well. I'm expecting, therefore, to always get an integral number of ATM cells in my incoming data. However, if I do large pings (for this example, I'm pinging the machine with a 4k ping size) into the machine, all of the data doesn't make it into my read urb. I'm assuming (for sake of discussion) that the time it takes me to process the first chunk of data (since the data is > than my transfer buffer, it has to come in multiple chunks) is too long and the rest of the data gets dropped? I don't see any errors from the usb or usb-uhci modules about data being dropped. But, I'm definitely not getting the full set of cells that makes up the whole 4k ping. So, I tried switching to a model where we queue multiple bulk read urbs. With this model, my urbs have smaller sizes, but they are often not sized relative to the ATM cell size. How is this all supposed to work - how does the usb code decide how much data to put into an urb?
Maybe my explanation is not clear. Tomorrow I'm going to put this on the CATC and see what the data looks like on the bus when running under Linux and when running on another platform (that works with large pings). Thanks, -Chris _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
