Re: USBCV MSC test failing

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Hi,

On 04/11/2011 07:11 PM, ext Alan Stern wrote:
On Mon, 11 Apr 2011, Roger Quadros wrote:

On 04/06/2011 10:11 PM, ext Alan Stern wrote:
On Wed, 6 Apr 2011, Sonasath, Moiz wrote:

All,

I am working on android kernel based on K35, and I see these bunch of
device configure failures. Any pointers would really help.

Which gadget driver are you using?

Have you enabled verbose debugging in the gadget driver?


I've kind of come to realize why this is happening.

It is a timing related issue. MSC tests issues two set configurations and set
interface (alt 0) and immediately follow with a CBW.

In the current composite framework + f_mass_storage setup, the actual enabling
and disabling of endpoints is done in a background thread, while the setup
requests are allowed to complete through composite.c.

(notice that DELAYED_RESPONSE is not correctly implemented here as in
file_storage.c)

I meant DELAYED_STATUS.


The CBW is received by the controller but due to large latency in scheduling the
thread to process the CONFIG_STATE_CHANGE state, the endpoints get reset after
the CBW is received, instead of before, thus loosing the CBW.

That certainly would explain the problem.

Can you come up with a patch for implemented DELAYED_RESPONSE properly
in the composite framework?  And maybe give it a name more suitable for
public use, like USB_GADGET_DELAYED_RESPONSE?

Yes, I'll try to come up with something.

--
regards,
-roger
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