Hi > -----Original Message----- > From: Roger Quadros [mailto:rogerq@xxxxxx] > Sent: Monday, April 25, 2016 10:04 PM > To: Jun Li <jun.li@xxxxxxx>; stern@xxxxxxxxxxxxxxxxxxx; balbi@xxxxxxxxxx; > gregkh@xxxxxxxxxxxxxxxxxxx; peter.chen@xxxxxxxxxxxxx > Cc: dan.j.williams@xxxxxxxxx; jun.li@xxxxxxxxxxxxx; > mathias.nyman@xxxxxxxxxxxxxxx; tony@xxxxxxxxxxx; Joao.Pinto@xxxxxxxxxxxx; > abrestic@xxxxxxxxxxxx; r.baldyga@xxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v6 09/12] usb: gadget: udc: adapt to OTG core > > Hi, > > On 21/04/16 09:38, Jun Li wrote: > > 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. > > It is upto the OTG state machine to call gadget_start() when it needs to > connect to the bus (i.e. loc_conn()). I see no point in calling gadget > start before. > > Do you see any issue in doing so? This is what OTG state machine does: case OTG_STATE_B_PERIPHERAL: otg_chrg_vbus(otg, 0); otg_loc_sof(otg, 0); otg_set_protocol(fsm, PROTO_GADGET); otg_loc_conn(otg, 1); break; You intend to abstract something common in this api when start gadget, which should be called by otg_set_protocol(fsm, PROTO_GADGET); and drd_set_protocol(fsm, PROTO_GADGET); right? So you may move usb_udc_connect_control(IMO usb_gadget_connect() is better)out of usb_gadget_start(), then for drd: case OTG_STATE_B_PERIPHERAL: drd_set_protocol(fsm, PROTO_GADGET); otg_drv_vbus(otg, 0); usb_gadget_connect(); Li Jun > > cheers, > -roger > > > > >> + > >> + 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 > > -- 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
