The interesting part of the problem I'm seeing is that it looks like, but I
haven't been able to verify/disprove yet, that not all of my completion
routine calls are being called when I get the USBNotSent2Err error.
Could this be possible? Without all of the completion routines being
called, I wouldn't have all of the reads queued that I was expecting, and
that would certainly go a long way towards explaining the problem that I'm
seeing.
Thanks,
Mark
On 2/27/06 9:24 AM, "David Ferguson" <email@hidden> wrote:
> The EHCI controllers found in the 17" Intel Core Duo iMac can look
> more than a millisecond ahead into scheduled periodic transactions
> (like high-speed isoch, or split-transactions to full-speed isoch
> device attached to a high-speed hub), if it doesn't see any
> transactions scheduled it can decide not to traverse the list at that
> time, even if a transaction is added later. This behavior will lead
> to more "USBNotSent2Err" -- Steve Sisak's suggestions for dealing
> with them is exactly correct. If you really want to avoid them
> altogether, just schedule your IN transactions further in the future.
>
> David Ferguson
> USB Software Team
> Apple Computer
>
> At 4:34 PM -0600 2/24/06, Mark Cookson wrote:
>> On the 17" Intel Core Duo iMac a couple of our USB audio devices get the
>> USBNotSent2Err on one of their interfaces.
>>
>> The particular device I'm looking at has three interfaces, two for input
>> (recording) and one for output (playback). It's only ever one of the input
>> interfaces that has the error, output is always fine, and the particular
>> interface changes from run to run. After getting this error (in frStatus
>> the completion routine) my standard bit of error correction isn't able to
>> get things going again, though no errors are reported from the pipe->Read()
>> call that's made after this error is returned.
>>
>> What's causing this error in the first place? And how should I try to
>> recover from it?
>>
>> I'm hoping that this means that my error correction is missing a case, but
>> I'm not seeing it. I'm hoping someone on this list can tell me more about
>> what the USBNotSent2Err means and how I should try to recover from it.
>>
>> These are isoc reads on a USB 1.1 device, Mac OS X 10.4.4 and 10.4.5, Intel
>> Macs seem to be far more likely (by orders of magnitude) to have this
>> problem than PPC ones.
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