From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752559AbdCFBQv (ORCPT ); Sun, 5 Mar 2017 20:16:51 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:35155 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752398AbdCFBQt (ORCPT ); Sun, 5 Mar 2017 20:16:49 -0500 Date: Mon, 6 Mar 2017 09:15:51 +0800 From: Peter Chen To: Heikki Krogerus Cc: Greg KH , Guenter Roeck , Felipe Balbi , Oliver Neukum , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Roger Quadros , Jun Li Subject: Re: [PATCH v17 2/3] usb: USB Type-C connector class Message-ID: <20170306011551.GA23305@b29397-desktop> References: <20170221142405.76299-1-heikki.krogerus@linux.intel.com> <20170221142405.76299-3-heikki.krogerus@linux.intel.com> <20170303033529.GA18650@b29397-desktop> <20170303143133.GB6999@kuha.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170303143133.GB6999@kuha.fi.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 03, 2017 at 04:31:33PM +0200, Heikki Krogerus wrote: > Hi Peter, > > On Fri, Mar 03, 2017 at 11:35:29AM +0800, Peter Chen wrote: > > On Tue, Feb 21, 2017 at 05:24:04PM +0300, Heikki Krogerus wrote: > > > +/* --------------------------------------- */ > > > +/* Driver callbacks to report role updates */ > > > + > > > +/** > > > + * typec_set_data_role - Report data role change > > > + * @port: The USB Type-C Port where the role was changed > > > + * @role: The new data role > > > + * > > > + * This routine is used by the port drivers to report data role changes. > > > + */ > > > +void typec_set_data_role(struct typec_port *port, enum typec_data_role role) > > > +{ > > > + if (port->data_role == role) > > > + return; > > > + > > > + port->data_role = role; > > > + sysfs_notify(&port->dev.kobj, NULL, "data_role"); > > > + kobject_uevent(&port->dev.kobj, KOBJ_CHANGE); > > > +} > > > +EXPORT_SYMBOL_GPL(typec_set_data_role); > > > + > > > > Hi Keikki, > > > > Have you tested this interface with real dual-role controller/board? > > Yes. Our boards are mostly USB dual-role capable. > > > What interface you use when you receive this event to handle > > dual-role switch? I am wonder if a common dual-role class is > > needed, then we can have a common user utility. > > > > Eg, if "data_role" has changed, the udev can echo "data_role" to > > /sys/class/usb-dual-role/role > > No. If the partner executes successfully for example DR_Swap message, > the kernel has to take care everything that is needed for the role to > be what ever was negotiated on its own. User space can't be involved > with that. > Would you give me an example how kernel handle this? How type-C event triggers role switch? -- Best Regards, Peter Chen