Roger, On Tue, Apr 12, 2011 at 12:18 AM, Roger Quadros <roger.quadros@xxxxxxxxx> wrote: > 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. > Any luck on this one? Any pointers on solving this one would really help. I tried a few things but no luck. > -- > regards, > -roger > -- Regards Moiz Sonasath Android Kernel Team -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
