On Sat, 2 Feb 2002, David Brownell wrote: > > My concern is what (if any) assumptions a driver might take about the > > order in which the corresponding completion callbacks are invoked. Would > > it be valid to rely on a fifo-like operation, i.e. the urb which was > > submitted first get completed first? > > For your case (c/b URBs queued to one endpoint) I think it must be. > After all, it's a queue ... queue jumpers not permitted! :)
Right, that's exactly the point. Do I understand you correctly, you are saying USB_QUEUE_BULK does not only deal with urbs being queued to the schedule (in submission order, of course), but the _same_ queueing is used for the corresponding completion callback? Would be very nice to know for sure. This would be a valuable feature IMHO. Note, for OHCI (EHCI probably as well) this appears quite natural since the HC maintains the donelist. Simply proceesing the callback in donelist-order gives the right thing. For UHCI however it all comes down to the way how the HCD collects the completed urbs. I did some look into both uhci drivers - but I don't feel I could tell for sure. And even if the current implementations would work this way I'd like to be sure it's by design - not simply coincidence. Martin _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
