On Wed, 24 Nov 2004, Pete Zaitcev wrote: > Hi, guys: > > I found that any attempt to connect an MCT U232 serial converter (mct_u232 > driver) to EHCI causes failures of usb_submit_urb with ENOSPC. This happens > at the very first interrupt URB submission. Anyone got any ideas how to > figure what's wrong? I looked at scheduling code and bandwidth allocation, > but I cannot figure it out. Needless to say, everything works fine with > OHCI and UHCI. > > Kernel 2.4.28-bk3.
This problem is actually discussed in the section about USB-2.0 support on www.linux-usb.org. Briefly, the EHCI driver doesn't implement support for isochronous transfers to full-speed devices lying behind a high-speed hub. If you plug the serial converter directly into the PC things should work better. Or if you plug it into a full-speed hub and plug the hub directly into the PC. Alan Stern ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
