On Tue, 10 Oct 2006 16:02:54 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote:
> On Tue, 10 Oct 2006, Christopher "Monty" Montgomery wrote:

> > Ah, EHCI (or USB in general) specifies a completion interrupt happens
> > only at the end of a frame?  I was suggesting the interrupt be thrown
> > as soon as the URB completes, even if that's mid-frame.

> Both UHCI and OHCI issue IRQs only at frame boundaries.  I believe EHCI 
> can issue IRQs at arbitrary uframe boundaries, but I'd have to check the 
> spec.  However I think ehci-hcd generally sets up the controller to issue 
> IRQs only at frame boundaries.  Dave knows more about that.

Is this the case for all kinds of transfers? I thought this was only true
for Interrupt and ISO, because my testing showed OHCI issuing interrupts
for end of bulk transfers at any time. I saw it in usbmon traces when
my host system allowed sub-jiffy resolution of a timestamp. But perhaps
I'm just delusional or do not remember correctly.

-- Pete

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