On 07/11/2012 03:37 AM, Dr. Ing. Dieter Jurzitza wrote:
Dear listmembers,
dear Sarah, dear Andiry,
Andiry's suggestion (uncomment the return 0 - statement) fixed my issue, the
usb soundcard remains active after a login-logout; however, as I understood
Sarah's comment this is no more than a plaster on the problem.
So, I am willing to do more testing - but I depend on your inputs as I am
lacking the required programming skills to actually understand what's
happening within the driver.
Please let me know what you'd suggest to do next ...
Thank you very much,
take care
Hi Dieter,
Thanks for the test.
Sarah,
I don't know why you regard it as an invalid fix and think the disabled
endpoint is abnormal.
See xHCI spec 4.6.6:
======================================================================
For each endpoint indicated by a Drop Context flag = '1':
If the Output Endpoint Context is not in the Disabled state:
The endpoint related resources are subtracted from the Resource
Required variable.
If the endpoint is periodic, then the bandwidth assigned to the
endpoint is subtracted from the bandwidth Required variable.
else // Output Endpoint Context is in the Disabled state:
Do nothing
======================================================================
Please note this is host controller behavior description, so "Do
nothing" means the host will do nothing with a Disabled endpoint with
drop flag = 1. It does not mean software should ignore the drop request
and return -EINVAL for SET_INTERFACE request.
And - Spec says what it should do with Disabled endpoint situation, that
implies the situation is expected - and also valid.
What do you think?
Thanks,
Andiry
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