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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