Comment 14 for bug 1033146
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| François Jacques (francois-jacques) wrote | #14 |
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bbfa235
(Get the code!)
Hi,
This is a development message which shouldn't be reported that often. It's not the root cause of issues seen with the LifeCam... just misleading.
I investigated the issue down to the kernel driver with additional traces. The set frequency operation at 48 khz goes through just fine, but the validation get frequency request performed right after isn't supported by the lifecam. The error code returned on that operation isn't 0, and in that case the driver issues that message. However, having a non-success for this operation is perfectly fine.
For more information, refer to USB Audio specification, when the adapter doesn't support such Get operation. See page 67 in http://
"If the addressed Control or Entity does not support readout of a certain attribute, the control pipe must
indicate a stall when an attempt is made to read that attribute."
So, IMHO, the warning that we see is a development warning, not a bug per se. The status code should be checked and the driver should remain silent UNLESS some really unexpected status code comes up.