From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Chen Subject: Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core Date: Tue, 26 Apr 2016 14:28:09 +0800 Message-ID: <20160426062809.GD2978@peterchendt> References: <1459865117-7032-1-git-send-email-rogerq@ti.com> <1459865117-7032-8-git-send-email-rogerq@ti.com> <20160426034711.GC2978@peterchendt> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jun Li Cc: Roger Quadros , "stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org" , "balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" , "gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org" , "peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org" , "dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "jun.li-KZfg59tc24xl57MIdRCFDg@public.gmane.org" , "mathias.nyman-VuQAYsv1563Yd54FQh9/CA@public.gmane.org" , "tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org" , "Joao.Pinto-HKixBCOQz3hWk0Htik3J/w@public.gmane.org" , "abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org" , "r.baldyga-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org" , "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-omap@vger.kernel.org On Tue, Apr 26, 2016 at 05:11:36AM +0000, Jun Li wrote: > Hi > > > -----Original Message----- > > From: Peter Chen [mailto:hzpeterchen-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org] > > Sent: Tuesday, April 26, 2016 11:47 AM > > To: Jun Li > > Cc: Roger Quadros ; stern-nwvwT67g6+6dFdvTe/nMLpVzexx5G7lz@public.gmane.org; > > balbi-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org; gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org; peter.chen-KZfg59tc24xl57MIdRCFDg@public.gmane.org; > > dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org; jun.li-KZfg59tc24xl57MIdRCFDg@public.gmane.org; > > mathias.nyman-VuQAYsv1563Yd54FQh9/CA@public.gmane.org; tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org; Joao.Pinto-HKixBCOQz3hWk0Htik3J/w@public.gmane.org; > > abrestic-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org; r.baldyga-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org; linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; > > linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > > Subject: Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core > > > > On Tue, Apr 26, 2016 at 02:07:56AM +0000, Jun Li wrote: > > > > +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"); > > > > > > dev_err, this should be an error. > > > > The condition may be wrong, but it is an information to show that current > > OTG is dual-role. > > This should not happen in any correct design, I even doubt if we > should try to continue by "downgrade" it to be duel role, currently > the only example user is dual role, so doing like this can't be > tested by real case, this downgrade is not so easy like we image, > at least for chipidea otg driver, simply replace a queue worker may > not work, as we have much more difference between the 2 configs. > Would you show more why chipidea can't work just replace the work item, and see if anything we still can improve for this framework? -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html