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RE: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup

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Hi,

(we don't top-post on this forum ;-)

"Du, Changbin" <changbin.du@intel.com> writes:
> Hi, Balbi,
>
> The step to reproduce this issue is:
> 1) connect device to a host and wait its enumeration.
> 2) trigger software disconnect by calling function
>     usb_gadget_disconnect(), which finally call
>    dwc3_gadget_pullup(false). Do not reconnect device
>   (I mean no enumeration go on, keep bit Run/Stop 0.).
>
> At here, gadget driver's disconnect callback should be
> Called, right? We has been disconnected. But no, as
> You said " not generating disconnect IRQ after you
> drop Run/Stop is expected".
>
> And I am testing on an Android device, Android only
> use dwc3_gadget_pullup(false) to issue a soft disconnection.
> This confused user that the UI still show usb as connected
> State, caused by missing a disconnect event.

okay, so I know what this is. This is caused by Android gadget itself
not notifying the gadget that a disconnect has happened. Just look at
udc-core's soft_connect implementation for the sysfs interface, and
you'll see what I mean.

This should be fixed at Android gadget itself. The only thing we could
do is introduce a new usb_gadget_soft_connect()/disconnect() to wrap the
logic so it's easier for Android gadget to use; but even that I'm a
little bit reluctant to do because Android should be using our
soft_connect interface instead of reimplementing it (wrongly) by its
own.

-- 
balbi

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[PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup changbin.du@intel.com - 2016-04-27 10:50 +0200
  Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-04-27 11:40 +0200
    RE: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn  off pullup "Du, Changbin" <changbin.du@intel.com> - 2016-04-27 13:30 +0200
      RE: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-04-28 08:50 +0200
        Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off  pullup John Youn <John.Youn@synopsys.com> - 2016-04-28 21:40 +0200
          Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-04-29 08:20 +0200
            Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off  pullup John Youn <John.Youn@synopsys.com> - 2016-05-02 03:50 +0200
              Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-05-04 12:50 +0200
                Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off  pullup John Youn <John.Youn@synopsys.com> - 2016-05-05 05:20 +0200
                Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-05-06 10:10 +0200
        Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn  off pullup Peter Chen <hzpeterchen@gmail.com> - 2016-05-05 10:20 +0200
          Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-05-06 09:10 +0200
            Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn  off pullup Peter Chen <hzpeterchen@gmail.com> - 2016-05-06 09:50 +0200
              Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off pullup Felipe Balbi <balbi@kernel.org> - 2016-05-06 10:00 +0200
  Re: [PATCH] usb: dwc3: usb/dwc3: fake dissconnect event when turn off  pullup Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-04-27 14:10 +0200

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