On Fri, Apr 15, 2016 at 02:00:46PM +0300, Roger Quadros wrote: > On 15/04/16 12:25, Peter Chen wrote: > > On Tue, Apr 05, 2016 at 05:05:12PM +0300, Roger Quadros wrote: > >> + * usb_otg_register() - Register the OTG/dual-role device to OTG core > >> + * @dev: OTG/dual-role controller device. > >> + * @config: OTG configuration. > >> + * > >> + * Registers the OTG/dual-role controller device with the USB OTG core. > >> + * > >> + * Return: struct usb_otg * if success, ERR_PTR() if error. > >> + */ > >> +struct usb_otg *usb_otg_register(struct device *dev, > >> + struct usb_otg_config *config) > >> +{ > >> + struct usb_otg *otg; > >> + struct otg_wait_data *wait; > >> + int ret = 0; > >> + > >> + if (!dev || !config || !config->fsm_ops) > >> + return ERR_PTR(-EINVAL); > >> + > >> + /* already in list? */ > >> + mutex_lock(&otg_list_mutex); > >> + if (usb_otg_get_data(dev)) { > >> + dev_err(dev, "otg: %s: device already in otg list\n", > >> + __func__); > >> + ret = -EINVAL; > >> + goto unlock; > >> + } > >> + > >> + /* allocate and add to list */ > >> + otg = kzalloc(sizeof(*otg), GFP_KERNEL); > >> + if (!otg) { > >> + ret = -ENOMEM; > >> + goto unlock; > >> + } > >> + > >> + otg->dev = dev; > >> + otg->caps = config->otg_caps; > >> + > >> + if ((otg->caps->hnp_support || otg->caps->srp_support || > >> + otg->caps->adp_support) && !config->otg_work) > >> + dev_info(dev, "otg: limiting to dual-role\n"); > > > > What does above mean? Customized otg_work item may be dual-role, > > may be full otg. > > I'm checking for !config->otg_work so we're sure of using the > default dual-role only work function. > I see. But whether it is dual-role or fully otg should depend on otg->caps, the work item may be different according to design. Besides, your code seems to depend on one of the otg capabilities for dual-role. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html