From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752138AbcERD1h (ORCPT ); Tue, 17 May 2016 23:27:37 -0400 Received: from mail-pa0-f66.google.com ([209.85.220.66]:35582 "EHLO mail-pa0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751095AbcERD1e (ORCPT ); Tue, 17 May 2016 23:27:34 -0400 Date: Wed, 18 May 2016 11:18:30 +0800 From: Peter Chen To: Roger Quadros Cc: peter.chen@freescale.com, balbi@kernel.org, tony@atomide.com, gregkh@linuxfoundation.org, dan.j.williams@intel.com, mathias.nyman@linux.intel.com, Joao.Pinto@synopsys.com, sergei.shtylyov@cogentembedded.com, jun.li@freescale.com, grygorii.strashko@ti.com, yoshihiro.shimoda.uh@renesas.com, robh@kernel.org, nsekhar@ti.com, b-liu@ti.com, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v8 13/14] usb: gadget: udc: adapt to OTG core Message-ID: <20160518031829.GA4244@shlinux2.ap.freescale.net> References: <1463133808-10630-1-git-send-email-rogerq@ti.com> <1463133808-10630-14-git-send-email-rogerq@ti.com> <20160516070249.GB24609@shlinux2.ap.freescale.net> <57398451.2060103@ti.com> <20160516092323.GD24609@shlinux2.ap.freescale.net> <57399839.90706@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57399839.90706@ti.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 16, 2016 at 12:51:53PM +0300, Roger Quadros wrote: > On 16/05/16 12:23, Peter Chen wrote: > > On Mon, May 16, 2016 at 11:26:57AM +0300, Roger Quadros wrote: > >> Hi, > >> > >> On 16/05/16 10:02, Peter Chen wrote: > >>> On Fri, May 13, 2016 at 01:03:27PM +0300, Roger Quadros wrote: > >>>> + > >>>> +static int usb_gadget_connect_control(struct usb_gadget *gadget, bool connect) > >>>> +{ > >>>> + struct usb_udc *udc; > >>>> + > >>>> + mutex_lock(&udc_lock); > >>>> + udc = usb_gadget_to_udc(gadget); > >>>> + if (!udc) { > >>>> + dev_err(gadget->dev.parent, "%s: gadget not registered.\n", > >>>> + __func__); > >>>> + mutex_unlock(&udc_lock); > >>>> + return -EINVAL; > >>>> + } > >>>> + > >>>> + if (connect) { > >>>> + if (!gadget->connected) > >>>> + usb_gadget_connect(udc->gadget); > >>>> + } else { > >>>> + if (gadget->connected) { > >>>> + usb_gadget_disconnect(udc->gadget); > >>>> + udc->driver->disconnect(udc->gadget); > >>>> + } > >>>> + } > >>>> + > >>>> + mutex_unlock(&udc_lock); > >>>> + > >>>> + return 0; > >>>> +} > >>>> + > >>> > >>> Since this is called for vbus interrupt, why not using > >>> usb_udc_vbus_handler directly, and call udc->driver->disconnect > >>> at usb_gadget_stop. > >> > >> We can't assume that this is always called for vbus interrupt so > >> I decided not to call usb_udc_vbus_handler. > >> > >> udc->vbus is really pointless for us. We keep vbus states in our > >> state machine and leave udc->vbus as ture always. > >> > >> Why do you want to move udc->driver->disconnect() to stop? > >> If USB controller disconnected from bus then the gadget driver > >> must be notified about the disconnect immediately. The controller > >> may or may not be stopped by the core. > >> > > > > Then, would you give some comments when this API will be used? > > I was assumed it is only used for drd state machine. > > drd_state machine didn't even need this API in the first place :). > You guys wanted me to separate out start/stop and connect/disconnect for full OTG case. > Won't full OTG state machine want to use this API? If not what would it use? > Oh, I meant only drd and fully otg state machine needs it. I am wondering if we need have a new API to do it. Two questions: - Except for vbus interrupt, any chances this API will be used at current logic? - When this API is called but without a coming gadget->stop? -- Best Regards, Peter Chen