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Subject: Re: usb: dwc3: gadget: skip pullup and set_speed after suspend
To:     eg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Daehwan Jung <dh10.jung@samsung.com>
Cc:     Felipe Balbi <balbi@kernel.org>,
        "open list:DESIGNWARE USB3 DRD IP DRIVER" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <CGME20210122065248epcas2p19a972d3a385b91d6e05a16f2ef7b0dd6@epcas2p1.samsung.com>
 <20210122064125.GA121941@ubuntu> <20210122071540.GB121941@ubuntu>
From:   Wesley Cheng <wcheng@codeaurora.org>
Message-ID: <c658e20c-299f-c748-ca48-e3351dcfffd2@codeaurora.org>
Date:   Tue, 26 Jan 2021 19:34:57 -0800
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On 1/21/2021 11:15 PM, Jung Daehwan wrote:
> On Fri, Jan 22, 2021 03:32, Wesley cheng wrote:
>> Hi Daehwan,
>>
>> If this is an unexpected event where userspace initiates the UDC bind
>> sequence, then after the above sequence occurs, the DWC3 device should
>> still be able to re-enter runtime suspend after the autosuspend timer
>> expires.  Since the cable is disconnected, the dwc->connected flag would
>> still be false.  Is this not happening in your situation?
>>
>> I'm just trying to understand what issue you're seeing other than the
>> momentary transition from runtime suspend (due to cable disconnect)
>> -->runtime resume (due to unexpected UDC bind) --> runtime  suspend (due
>> to nothing connected).
>>
>> Thanks
>> Wesley cheng
> 
> Hi Wesley,
> 
> I don't know why but DWC3 device is not re-entering runtime-suspend in
> my situation. I'm still debugging it.
> Even if DWC3 re-enter runtime-suspend but it doesn't mean stopping gadget.
> Are you stopping gadget manually in this case?

Hi Daehwan,

Sorry for the late response.  So during the DWC3 runtime suspend path,
we will execute dwc3_gadget_suspend() which should disable the gadget
events and disable ep0 then clear RS bit.  Then on runtime resume, the
DWC3 will be re-enabled, and the RS bit set again.

Thanks
Wesley Cheng

> 
> Best Regards,
> Jung Daehwan
> 
> 

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