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Re: Potential problem with reading data from usb devices with ugen(4)



Brian Buhrow <buhrow%nfbcal.org@localhost> writes:

> 	hello.  I don't necessarily need the read ahead functionality, though
> it might be useful when I start doing large transfers to and from the Apple
> devices.  However, what I want is the non-blocking functionality which,
> according to the manual, requires I use the read ahead code to get.  It
> appears, however, that the non-blocking functionality is minimally tested
> and may not work as advertised.  Also, it looks like the timeout
> functionality may not be quite right either, though I've not investigated
> that as thoroughly yet.

So perhaps we should step back and ask why non-blocking doesn't work.
Part of it is that reading from a USB device causes bus transactions, so
even reading is an active step.  The next question is if it makes sense
within USB to have a pending read, or if you can try to read and either
succeed or find nothing.   I think we need a really clear understanding
of all of that (which I may have had at one point) before trying to fix.

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