Am Mittwoch, 2. Januar 2008 schrieb David Brownell:
> On Tuesday 01 January 2008, Karsten Wiese wrote:
> > How about:
> > Urbs stopping/starting at (uFrame % 8) != 0 can share ITDs,
>
> If there's a problem in that area, it should get fixed in a
> patch just addressing that issue. Did you mention such an
> issue before?
Don't know. Its a feature to let n ITD's suffice, where currently
n + 1 are used.
I.e. streaming urbs with nr_of_packets=22.
It might make things easier for the ehci-silicon too:
Only 1 ITD to look at for a given pipe and frame.
>
>
> > The finishing urb doesn't recycle its last ITD, instead the starting urb
> > takes care of that.
>
> Also a different issue. The patch I posted to defer the recycling
> on URB completion paths suffices,
Not I think. I don't mean its wrong, there's 1 thing missing though,
see below.
> given the assumptions that only
> completions will add to the schedule and that drivers aren't doing
> silly stuff like more than two URBs per frame (for a given endpoint).
>
>
> > IIRC it was also necessary to never change a running (USB1.1) frame's
> > hardware schedule...
>
> A frame is a frame is a frame; USB 2.0 didn't change that!
>
> Again, not an issue given those assumptions.
Disagree: with your patches ITDs can still be removed from ehci's
hardware schedule, while a frame is active, no?
In scan_periodic()'s case Q_TYPE_ITD:
those lines:
*q_p = q.itd->itd_next;
*hw_p = q.itd->hw_next;
IMO should only execute once the frame has elapsed.
>
>
> > I've once succesfully tested this scheme.
> > It made ITD (de)scheduling a bit more complex.
> > Good is it needs less memory and DMA bandwith.
>
> It's not clear to me what you mean by these comments.
I meant:
"It worked fine here some month ago streaming iso urbs
containing odd nr_of_packets"
+ some course cost/benefit analysis.
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