On 10/15/06, Alan Stern <[EMAIL PROTECTED]> wrote: > Yes, differing interpretations. Perhaps we should introduce a new URB > submission flag, such as URB_ISO_STRICT, which would mean to schedule each > packet for its intended slot even if it's already too late. That way the > driver could choose which policy to follow.
I've seen the equivalent of ISO_ASAP in other drivers and had assumed there was a standard set that USB defined or at least recommended.... > > I hope we agree that on URB completion, start_frame indicates when that > > frame started. > > When the URB started, yes. Or was nominally scheduled to start in the > case of URB_ISO_STRICT, since it didn't actually start until some time > later. What happens when the driver specifies a frame that differs from the slot is was scheduled into? Take the next available? Reject? "Do what I say, damn the budget, no questions"? If scheduled into a slot different than the requested one, I assume we'd have to modify the start_frame field. Any of these are easily possible, which is most correct? This is beginning to feel like it's on the cusp of being hashed out enough to impelement. > > > My understanding of start_frame on urb submission was that originally > > the idea was: if ISO_ASAP wasn't set, that would specify the start frame. > > Now, I know that OHCI never implemented that; and EHCI didn't either. > > Maybe one of the UHCIs did/does. > > Currently it does. Of course this whole area is subject to change -- > once we all agree on what it should change to! Which of the options I listed above is closes to what UHCI currently does? Monty ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
