In article <[EMAIL PROTECTED]>, Craig Boston <[EMAIL PROTECTED]> writes >Believe it or not, after futzing with the debugger for hours, reading the OHCI >spec, and trying to figure out why writing to the control registers works >exactly as it should but the card seems to ignore the ED list, I decided to >try something completely crazy and put the line > >pci_enable_busmaster(self); > >near the top of ohci_attach() in ohci_pci.c > >...and it worked! I believe my first words upon seeing "ums0: <blah blah>" >were "You have GOT to be kidding me."
Great news. >I'm attaching a (trivial) patch for the lazy :) Be advised, this is far from >a general solution as it probably breaks some (many?) PCI-based controllers >that don't support bus mastering. Sorry, I don't understand this comment. All OHCI, UHCI & EHCI USB controllers need PCI bus mastering in order to read & update their various lists of pending & completed transfers. Without bus mastering the system CPU has to do all this stuff in an interrupt handler. This can be quite a heavy cpu load, and is not attractive on a PC. (I've outlined this before, on [EMAIL PROTECTED] E.g. the ScanLogic SL811 needs an interrupt for every packet transfer, and Philips PHCI devices [e.g. ISP1160] needs a whole frame's worth of data to read & written every ms.) Cheers, Tony _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
