On Sun, 14 Nov 2010, Pete Zaitcev wrote:
> > > + while (ndesc-- != 0) {
> > > + if (fp->status == 0 && fp->actual_length != 0) {
> >
> > I'd leave out the fp->status == 0 test. It's not relevant; a buffer
> > can contain valid data even if the final status isn't 0.
>
> That's a good point, however is actual_length filled in such case?
> I thought it was either one or the other.
No, it's possible to have both. This is less likely with isochronous
than with the other transfer types, but it can happen. For example,
consider a high-bandwidth high-speed transfer where 3072 bytes are
received in three packets during a single microframe. You might
receive two of the three packets, giving actual_length = 2048, and then
not receive the third, giving status = -EPROTO.
Alan Stern
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