From: Jun Li <jun.li@nxp.com>
To: Roger Quadros <rogerq@ti.com>,
        "stern@rowland.harvard.edu" <stern@rowland.harvard.edu>,
        "balbi@kernel.org" <balbi@kernel.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "peter.chen@freescale.com" <peter.chen@freescale.com>
CC: "dan.j.williams@intel.com" <dan.j.williams@intel.com>,
        "jun.li@freescale.com" <jun.li@freescale.com>,
        "mathias.nyman@linux.intel.com" <mathias.nyman@linux.intel.com>,
        "tony@atomide.com" <tony@atomide.com>,
        "Joao.Pinto@synopsys.com" <Joao.Pinto@synopsys.com>,
        "abrestic@chromium.org" <abrestic@chromium.org>,
        "r.baldyga@samsung.com" <r.baldyga@samsung.com>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>
Subject: RE: [PATCH v6 09/12] usb: gadget: udc: adapt to OTG core
Thread-Topic: [PATCH v6 09/12] usb: gadget: udc: adapt to OTG core
Thread-Index: AQHRj0RV7MO/tAbHz06QbtTGgchQCZ+UDbgw
Date: Thu, 21 Apr 2016 06:38:16 +0000
Message-ID: <AM4PR04MB2130ACE0588E64EA723987E3896E0@AM4PR04MB2130.eurprd04.prod.outlook.com>
References: <1459865117-7032-1-git-send-email-rogerq@ti.com>
 <1459865117-7032-10-git-send-email-rogerq@ti.com>
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Hi,

...
> 
>  /**
> + * usb_gadget_start - start the usb gadget controller and connect to
> +bus
> + * @gadget: the gadget device to start
> + *
> + * This is external API for use by OTG core.
> + *
> + * Start the usb device controller and connect to bus (enable pull).
> + */
> +static int usb_gadget_start(struct usb_gadget *gadget) {
> +	int ret;
> +	struct usb_udc *udc = NULL;
> +
> +	dev_dbg(&gadget->dev, "%s\n", __func__);
> +	mutex_lock(&udc_lock);
> +	list_for_each_entry(udc, &udc_list, list)
> +		if (udc->gadget == gadget)
> +			goto found;
> +
> +	dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
> +		__func__);
> +	mutex_unlock(&udc_lock);
> +	return -EINVAL;
> +
> +found:
> +	ret = usb_gadget_udc_start(udc);
> +	if (ret)
> +		dev_err(&udc->dev, "USB Device Controller didn't start: %d\n",
> +			ret);
> +	else
> +		usb_udc_connect_control(udc);

For drd, it's fine, but for real otg, gadget connect should be done
by loc_conn() instead of gadget start.

> +
> +	mutex_unlock(&udc_lock);
> +
> +	return ret;
> +}
> +
> +/**
> + * usb_gadget_stop - disconnect from bus and stop the usb gadget
> + * @gadget: The gadget device we want to stop
> + *
> + * This is external API for use by OTG core.
> + *
> + * Disconnect from the bus (disable pull) and stop the
> + * gadget controller.
> + */
> +static int usb_gadget_stop(struct usb_gadget *gadget) {
> +	struct usb_udc *udc = NULL;
> +
> +	dev_dbg(&gadget->dev, "%s\n", __func__);
> +	mutex_lock(&udc_lock);
> +	list_for_each_entry(udc, &udc_list, list)
> +		if (udc->gadget == gadget)
> +			goto found;
> +
> +	dev_err(gadget->dev.parent, "%s: gadget not registered.\n",
> +		__func__);
> +	mutex_unlock(&udc_lock);
> +	return -EINVAL;
> +
> +found:
> +	usb_gadget_disconnect(udc->gadget);

Likewise, gadget disconnect also should be done by loc_conn()
instead of gadget stop.

> +	udc->driver->disconnect(udc->gadget);
> +	usb_gadget_udc_stop(udc);
> +	mutex_unlock(&udc_lock);
> +
> +	return 0;
> +}
> +

Li Jun