From: John Youn <John.Youn@synopsys.com>
To: John Stultz <john.stultz@linaro.org>,
        lkml <linux-kernel@vger.kernel.org>
CC: Wei Xu <xuwei5@hisilicon.com>, Guodong Xu <guodong.xu@linaro.org>,
        "Amit Pundir" <amit.pundir@linaro.org>,
        Rob Herring <robh+dt@kernel.org>, John Youn <John.Youn@synopsys.com>,
        Douglas Anderson <dianders@chromium.org>,
        Chen Yu <chenyu56@huawei.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: [PATCH v2] usb: dwc2: Make sure we disconnect the gadget state
Thread-Topic: [PATCH v2] usb: dwc2: Make sure we disconnect the gadget state
Thread-Index: AQHSqQUI42PQRyOmy0qV1VZrw7hUGw==
Date: Mon, 3 Apr 2017 01:59:14 +0000
Message-ID: <2B3535C5ECE8B5419E3ECBE300772909021B4A4060@US01WEMBX2.internal.synopsys.com>
References: <1490844216-32085-1-git-send-email-john.stultz@linaro.org>
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On 03/29/2017 08:23 PM, John Stultz wrote:
> I had seen some odd behavior with HiKey's usb-gadget interface
> that I finally seemed to have chased down. Basically every other
> time I plugged in the OTG port, the gadget interface would
> properly initialize. The other times, I'd get a big WARN_ON
> in dwc2_hsotg_init_fifo() about the fifo_map not being clear.
>
> Ends up if we don't disconnect the gadget state, the fifo-map
> doesn't get cleared properly, which causes WARN_ON messages and
> also results in the device not properly being setup as a gadget
> every other time the OTG port is connected.
>
> So this patch adds a call to dwc2_hsotg_disconnect() in the
> reset path so the state is properly cleared.
>
> With it, the gadget interface initializes properly on every
> plug in.
>
> Cc: Wei Xu <xuwei5@hisilicon.com>
> Cc: Guodong Xu <guodong.xu@linaro.org>
> Cc: Amit Pundir <amit.pundir@linaro.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: John Youn <johnyoun@synopsys.com>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Chen Yu <chenyu56@huawei.com>
> Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: linux-usb@vger.kernel.org
> Acked-by: John Youn <johnyoun@synopsys.com>
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
> v2: Minor typo fix suggested by Sergei Shtylyov
> ---
>  drivers/usb/dwc2/hcd.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index a73722e..91ed5b6 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -3264,6 +3264,7 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
>  		dwc2_core_init(hsotg, false);
>  		dwc2_enable_global_interrupts(hsotg);
>  		spin_lock_irqsave(&hsotg->lock, flags);
> +		dwc2_hsotg_disconnect(hsotg);
>  		dwc2_hsotg_core_init_disconnected(hsotg, false);
>  		spin_unlock_irqrestore(&hsotg->lock, flags);
>  		dwc2_hsotg_core_connect(hsotg);
>


Hi Felipe,

You may want to use this patch to replace the one in your testing/next
as this has a cleaner commit message.

Thanks,
John