> > For example, let's say an URB is submitted for slot S, just as S's > > microframe is starting. ehci-hcd adds the URB into the hardware schedule; > > was it in time for the controller to see it?
Right now, that attempt would be outright rejected. ehci-sched will not (and never would) schedule into the currently active frame. In fact, it would not schedule into any frame within 'SCHEDULE_SLOP' of the active frame. I did not change that behavior. > No way to know until the > > microframe is finished. The only way ehci-hcd can make an accurate report > > in this case is to _always_ report that the slot was missed -- not even > > _try_ to add it into the hardware schedule -- even if it might have been > > possible for the slot to be filled. ...or check the uframe clock when the schedule is complete and if it still precedes the slot... [or are you worried about caching and propogation of changes?] > Actually that's a good description of the case where that -EXDEV fault > might reasonably be reported at completion. Yes, agreed, if we really can't reliably figure it out ahead of time. > And I was wrong about EHCI (at least) reporting that ... since that's > the initial value for each (micro)frame's transfer status, EHCI will > report that when collecting an ITD that sitll has ITD_ACTIVE set. > But, hmm bug!, not (yet) SITDs with SITD_ACTIVE. (Monty, that would > seem to be something you might fix in one of your patchsets ... it's > trivial, but I don't want to create needless problems for your patches!) Yes, good catch. I'll make that change. Monty > > - Dave > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
