RE: [PATCH v6 09/12] usb: gadget: udc: adapt to OTG core

From: Jun Li
Date: Thu Apr 21 2016 - 02:38:25 EST


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