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Subject: Re: [REGRESSION] "dwc2: gadget: fix TX FIFO size and address
 initialization" breaks "adb logcat" on hikey
To: John Stultz <john.stultz@linaro.org>,
        Robert Baldyga <r.baldyga@samsung.com>,
        John Youn <John.Youn@synopsys.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>
References: <CALAqxLU4ak7BGnA+nyr7Bata_5LG0Pnh1N=314sDo6L3gGrcJw@mail.gmail.com>
CC: lkml <linux-kernel@vger.kernel.org>,
        Amit Pundir <amit.pundir@linaro.org>,
        Guodong Xu <guodong.xu@linaro.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
From: John Youn <John.Youn@synopsys.com>
Message-ID: <e6236cd9-d765-aa1f-f266-48ae88089617@synopsys.com>
Date: Thu, 6 Oct 2016 11:24:34 -0700
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On 10/5/2016 11:33 PM, John Stultz wrote:
> Hey folks,
>    So I've run into some trouble that I've narrowed down to commit
> aa381a7259c3 ("usb: dwc2: gadget: fix TX FIFO size and address
> initialization").
> 
> After booting up android on HiKey, if I run "adb logcat", I get about
> a page of logs and then I get disconnected.  On the device side, I see
> the following in dmesg:
> 
> [   35.652076] dwc2 f72c0000.usb: dwc2_hsotg_ep_sethalt(ep
> ffffffc078a4c218 ep1in, 0)
> [   35.660334] dwc2 f72c0000.usb: dwc2_hsotg_ep_sethalt(ep
> ffffffc078a4c018 ep1out, 0)
> 
> After which if I stop adbd I see:
> 
> [   99.471363] dwc2 f72c0000.usb: dwc2_hsotg_ep_stop_xfr: timeout flushing fifos
> 
> and if I then restart adbd on the device it will sometimes work, but not always.
> 
> Reverting
> ba48eab8866c ("usb: dwc2: gadget: change variable name to more meaningful")
> and
> aa381a7259c3 ("usb: dwc2: gadget: fix TX FIFO size and address initialization")
> 
> makes things work again.
> 
> Any thoughts as to what might be going wrong here? I'd be happy to
> help debug things.
> 
> thanks
> -john
> 


Hi John,

Yup. I've already submitted patches to revert these last week, to be
applied sometime during the 4.9-rc cycle. We're working on a more
robust fix for the FIFOs too.

Regards,
John