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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9F37C433EF for ; Thu, 17 Feb 2022 15:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242473AbiBQP3G (ORCPT ); Thu, 17 Feb 2022 10:29:06 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242461AbiBQP3G (ORCPT ); Thu, 17 Feb 2022 10:29:06 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E2612AB508; Thu, 17 Feb 2022 07:28:52 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9DD3561E9F; Thu, 17 Feb 2022 15:28:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ABFFC340E8; Thu, 17 Feb 2022 15:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645111731; bh=ru4JYpuY+BIPB6TA0dGc9lns/k0eZgQxIgm7/e+BfO0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=U8Xn12Sz0aqZ0kUd9SIDuRVaNIFErQA7sEq0vQ93pD1F9eGNfLhDxZyq+YKJ8AEAJ 56zIF669Xc4GtDNb0wnI9Kq5/LvUGUP6qaYzCvD7mAA4BBOx6NdHNW0CB5GetivmQJ ChmoP8uBazLnjAm2cSULKoV+JPxOcbE4I5wlLnPA= Date: Thu, 17 Feb 2022 16:28:48 +0100 From: Greg KH To: Jing Leng <3090101217@zju.edu.cn> Cc: balbi@kernel.org, ruslan.bilovol@gmail.com, pavel.hofman@ivitera.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Jing Leng Subject: Re: [PATCH] usb: gadget: f_uac1: add set requests support Message-ID: References: <20220216094301.2448-1-3090101217@zju.edu.cn> <770c0d3f.ab34b.17f0557e359.Coremail.3090101217@zju.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <770c0d3f.ab34b.17f0557e359.Coremail.3090101217@zju.edu.cn> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Feb 17, 2022 at 09:42:00AM +0800, Jing Leng wrote: > Hi Greg KH, > > > So is this a bug in the Host side to not do stuff like this? Why not > > fix it there instead? > > > > Where is the requirement that this command must be handled by the > > device? > > > > First we need to clarify two issues. > > 1. Does the Ubuntu go beyond the UAC1 specification? > No. > On page 66 of the UAC1 specification ( > https://www.usb.org/sites/default/files/audio10.pdf): > The bRequest can be SET_CUR, SET_MIN, SET_MAX, SET_RES or SET_MEM. > In most cases, only the CUR and MEM attribute will be supported for > the Set request. However, this specification does not prevent a > designer from making other attributes programmable. > Supplement: Windows 10 only sends SET_CUR request. > > 2. Does the old version kernel have the problem on the Ubuntu? > NO. (e.g. linux-5.10) > The problem is introduced by the following modification: > commit 0356e6283c7177391d144612f4b12986ed5c4f6e > Author: Ruslan Bilovol > Date: Mon Jul 12 14:55:29 2021 +0200 > > usb: gadget: f_uac1: add volume and mute support Then please add this commit id as a "Fixes:" tag in the changelog area. thanks, greg k-h