From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01358C4338F for ; Wed, 25 Aug 2021 07:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC471611F0 for ; Wed, 25 Aug 2021 07:01:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238577AbhHYHBz (ORCPT ); Wed, 25 Aug 2021 03:01:55 -0400 Received: from mga18.intel.com ([134.134.136.126]:58094 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238342AbhHYHBy (ORCPT ); Wed, 25 Aug 2021 03:01:54 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10086"; a="204598664" X-IronPort-AV: E=Sophos;i="5.84,349,1620716400"; d="scan'208";a="204598664" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Aug 2021 00:01:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,349,1620716400"; d="scan'208";a="597924473" Received: from kuha.fi.intel.com ([10.237.72.162]) by fmsmga001.fm.intel.com with SMTP; 25 Aug 2021 00:01:05 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Wed, 25 Aug 2021 10:01:05 +0300 Date: Wed, 25 Aug 2021 10:01:05 +0300 From: Heikki Krogerus To: Felipe Balbi Cc: Nehal Bakulchandra Shah , gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kun.liu2@amd.com, alexander.deucher@amd.com Subject: Re: [RESEND PATCH 2/2] usb: dwc3: pci add property to allow user space role switch Message-ID: References: <20210824192337.3100288-1-Nehal-Bakulchandra.shah@amd.com> <87ilzu5ap0.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ilzu5ap0.fsf@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Aug 25, 2021 at 08:55:41AM +0300, Felipe Balbi wrote: > > Hi, > > Nehal Bakulchandra Shah writes: > > > For AMD platform there is a requirement to enable user space role > > switch from host to device and device to host as customer platform is not > > completely capable of OTG i.e. with type C controller it does not have PD > > to support role switching. Hence, based ACPI/EC interrupt role switch is > > triggered by the usemode script running in background. > usermode ? Couldn't you capture that ACPI/EC interrupt in kernel? > > Signed-off-by: Nehal Bakulchandra Shah > > I'm okay with this, just wondering if we need to Document the property > somewhere. > > @Heikki, is there a place to document these private properties that's > not on DT binding document? The build-in properties are not documented separately. I've always tried to supply DT bindings for all new properties I've proposed. In this case though, do we need the new property at all? Why not just register a normal USB role switch on this platform? It can be either a dummy role switch that only passes the user space input to dwc3, or, perhaps ideally, it would also be a driver that captures that ACPI/EC event/notification and then passes the information from it to dwc3. thanks, -- heikki