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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 0F4C1C4338F for ; Tue, 24 Aug 2021 16:18:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E28336125F for ; Tue, 24 Aug 2021 16:18:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231292AbhHXQSw (ORCPT ); Tue, 24 Aug 2021 12:18:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:53756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230465AbhHXQSv (ORCPT ); Tue, 24 Aug 2021 12:18:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 43756610A3; Tue, 24 Aug 2021 16:18:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629821887; bh=BDlMQu45ZqDbJNs8wpBo7h9vi71+LyNyrpawT/E6PIY=; h=References:From:To:Cc:Subject:Date:In-reply-to:From; b=Xf2/5TI3Njr4zvViw5ydr4E55iYT1FHPGYtCCAPxYhjAws82Cr8Sf4YDd/s+NY/Bh tKHi2V4+QO5VZiDkIi47l3gJT1WyDX0OHknJqc/S+pOqECz/udMdNUJNgJz3UZGCAW lvFVPPw21rFotw/dUG3Zs3ym18o75DHIpwSw+sxhJATBUnlJtfCLjWWFFQU7iLG9WB 8vPm3bIIohODS3Fw9kPK+Tv8hYDpAfzuzhIjn8ltUOoU5AD+jppSxGNweJROjHdXG/ BhtfNbJu9rMu77LvT2ss12hJK60Tqe1IZ3br+ib6MGsC9/xuYxh4tdwfViXtTW3ceN UGJRZe0H2hqdQ== References: <20210823184449.2796184-1-Nehal-Bakulchandra.shah@amd.com> <20210823184449.2796184-3-Nehal-Bakulchandra.shah@amd.com> <87pmu36ypp.fsf@kernel.org> <1d9ecba4-d180-2193-66a3-3812759e1916@amd.com> User-agent: mu4e 1.6.4; emacs 27.2 From: Felipe Balbi To: "Shah, Nehal-bakulchandra" Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, kun.liu2@amd.com, alexander.deucher@amd.com Subject: Re: [PATCH 2/2] usb: dwc3: pci add property to allow user space role switch Date: Tue, 24 Aug 2021 19:17:46 +0300 In-reply-to: <1d9ecba4-d180-2193-66a3-3812759e1916@amd.com> Message-ID: <87czq27r5w.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org "Shah, Nehal-bakulchandra" writes: > Hi > On 8/24/2021 1:49 PM, Felipe Balbi wrote: >> 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 by means of running >>> following commands. >>> >>> HOST: echo host > /sys/class/usb_role/dwc3.0.auto-role-switch/role >>> DEVICE: echo device > /sys/class/usb_role/dwc3.0.auto-role-switch/role >> A more important question that needs to be answered: why? >> > Our customer platform is not completely capable of OTG i.e with type C > controller it does not have PD to support role switching. Hence, they > have script which triggers the role switch based on ACPI/EC interrupt. sounds like some generalized version of this text should be added to commit log. -- balbi