From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752253AbcFVKEI (ORCPT ); Wed, 22 Jun 2016 06:04:08 -0400 Received: from mga11.intel.com ([192.55.52.93]:42307 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446AbcFVKDr (ORCPT ); Wed, 22 Jun 2016 06:03:47 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,509,1459839600"; d="scan'208";a="1002916377" Date: Wed, 22 Jun 2016 13:03:16 +0300 From: Heikki Krogerus To: Oliver Neukum Cc: Greg KH , Guenter Roeck , Felipe Balbi , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCHv3 1/2] usb: USB Type-C connector class Message-ID: <20160622100316.GD19856@kuha.fi.intel.com> References: <1466520711-125758-1-git-send-email-heikki.krogerus@linux.intel.com> <1466520711-125758-2-git-send-email-heikki.krogerus@linux.intel.com> <1466540705.2014.11.camel@suse.com> <20160622095016.GB19856@kuha.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160622095016.GB19856@kuha.fi.intel.com> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 22, 2016 at 12:50:16PM +0300, Heikki Krogerus wrote: > On Tue, Jun 21, 2016 at 10:25:05PM +0200, Oliver Neukum wrote: > > On Tue, 2016-06-21 at 17:51 +0300, Heikki Krogerus wrote: > > > +What: /sys/class/typec//supported_data_roles > > > +Data: June 2016 > > > +Contact: Heikki Krogerus > > > +Description: > > > + Lists the USB data roles, host or device, the port is > > > capable > > > + of supporting. > > > > On third thought, this is a problem. Looking at 4.4.8.1 > > DEVICE_CAPABILITIES (Required) of USB Type-C Port Controller > > Interface Specification we lack capability. > > > > A port that can do DRP is not the same thing as a port that > > can be switched between DFP and UFP. We cannot express that. > > What do you mean? DRP means we support and are able to swap the data > role, but it just does not mean we can act as both source and sink. And > that information we already get from separate attribute: > "supported_power_roles". > > But if the port is DRP, we will always be able to swap the data role > between DFP and UFP. Just to clarify: DRP as it's defined in Type-C spec < 1.2 means the data role, not power role. And that is what Universal Serial Bus Type-CTM Port Controller specification is based on. Please correct me if I'm wrong. Thanks, -- heikki