On Wed, 7 Oct 2009, Sarah Sharp wrote: > If I were to want the EHCI host controller to not schedule new iTDs > within the IST, would this patch do that? It would have to be applied > on top of my last patch for the isoc boundary checking bug fix. It sort of would. IMO a better approach would be to leave "now" as it is and introduce a new variable next = (now + ehci->i_thresh) % mod; However there are a few problems with your approach. First of all, the initial setting of ehci->i_thresh in ehci_init() is wrong; if the controller uses frame caching then the value should be 9 rather than 8 (i.e., a full frame plus one uframe uncertainty). Secondly, your patch would affect the way new streams are scheduled; they would be delayed unnecessarily. SCHEDULE_SLOP is already bigger than the threshold. Finally, I don't understand why you want to avoid scheduling new iTDs during the scheduling threshold. Changing this could break applications that require isochronous transfers to occur at a fixed reliable rate. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
