On Thu, 7 Jun 2007, Steinar H. Gunderson wrote: > On Thu, Jun 07, 2007 at 01:04:12PM -0400, Alan Stern wrote: > >> For some reason, it actually works without such a patch. Don't ask me why > >> :-) > > Probably because you're not using UHCI. > > Well, I'm not using OHCI, but I guess you're referring to that I'm using > EHCI?
EHCI doesn't drive low-speed devices directly; it works only at high-speed. Unless you're using specialized EHCI hardware or have attached the device through a high-speed hub, low- and full-speed devices are handed over to a companion controller, either UHCI or OHCI. > Another explanation would be that it actually _does_ send bulk > transfers after all; I haven't commented back in the check against low-speed > bulk transfers. However, the dumps from usbmon suggest interrupt outputs > _and_ inputs... There's no inherent difference between bulk and interrupt transfers, so it doesn't make sense to say that the controller sends a bulk transfer rather than an interrupt transfer. All that distinguishes them is how they are scheduled. The dumps from usbmon show the transfer type as it was passed to usbcore by the driver. They don't necessarily agree with the actual endpoint type. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
