Alan Stern wrote:
On Thu, 17 Jul 2003, David Brownell wrote:


OK, so it's possible that some of these problems start because the
chip is making a nonsensical response ... perhaps not unexpected,
since it wasn't actually running firmware at that point.


Since the test program is intended for detecting non-conforming hard/firm/software, I would expect it to be able to deal with all sorts of responses, including nonsensical ones.

Of the half dozen (or more!) components which can interact to produce failures, this code was originally designed to test only HCDs -- with the rest of the components being fixed "known working" quantities.

I wouldn't mind seeing patches submitted to behave better
with certain device errors, but I certainly wouldn't have
expected software that tests HCDs, by using "known good"
devices, to do much when used with malfunctioning devices.
That's an entirely different kind of test scenario, one
which needs a different approach.

On the other hand, it certainly did "detect" a non-conforming
device.  If you've got a way to have it report that error
in a better way, one that doesn't reduce the effectiveness of
the "test that HCD" role, submit a patch!  (Maybe just taking
more care in the unlink path, setting an explicit "this test
is stopping" flag and checking it, would handle this device.)



Remember that those tests require devices that behave
more or less correctly.  Garbage in, Garbage out.  It
would seem that without firmware, the FX is reporting
garbage when asked to report the altsetting.


Could be.

Returning a ZLP is not a legal response in that case, it's clearly not conforming to the USB protocol.


Sorry about that; I didn't think it would make much difference. These three URBs are the unlinked second-loop instances of subtests 0, 1, and possibly 3. I don't know why there doesn't seem to be any subtest 2 in the second loop.

Because when subtest 2 failed the first time around, the looping was all supposed to stop. If we assume the device misbehavior prevented the queue from being processed correctly, that would explain the "out of order" for subcase 3.


Can you suggest any additional diagnostics that might help?

I thought the diagnostics were already sufficient to diagnose the problem as a malfunctioning device, from what you said.

- Dave





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