>> > However, I don't think BW can be calculated effectively by common code, it
>> > is dependent on the HCD.
>>
>>That's how it behaves already, with the different HCDs putting more
>>or less work into their scheduling policy.
> 
> 
> That's how it is done now, but since the original code was the same
> across all HCD's, I don't see why it should differ between HCD's.

Because the HCDs do scheduling differently.  UHCI can significantly
undercommit periodic bandwidth, and does no balancing.  OHCI does
balancing, so it does a lot less undercommitting.  EHCI doesn't do
much periodic scheduling yet;  drivers haven't needed it, and anyway
its problem is about ten times harder because of split transactions.


> USB 1.1 is the same across all HCD's. The only thing I can think of that
> would differ is what frames interrupt URB's get scheduled into.

Example, the balancing that OHCI does to even out loads.  (Which
applies equally to iso transfers -- they don't need to run every
frame, though they often seem to.)


> Regardless, this isn't a big deal. If it's the same, put it into the
> core, if it isn't, put it into the HCD's.
> 
> JE
> 
> 





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