Received: by 2002:a6b:fb09:0:0:0:0:0 with SMTP id h9csp450167iog; Wed, 29 Jun 2022 03:41:52 -0700 (PDT) X-Google-Smtp-Source: AGRyM1t11i46WGZb5ROqAcdeE6VqLnoV22zDPVPTYuCyWeE/ZlOAwtLAydRMUXC1Xc/u2mlns4xj X-Received: by 2002:a17:907:da7:b0:726:9c0b:708b with SMTP id go39-20020a1709070da700b007269c0b708bmr2640290ejc.595.1656499311788; Wed, 29 Jun 2022 03:41:51 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1656499311; cv=none; d=google.com; s=arc-20160816; b=ifiocp05NXei9T2R+Hbb9NeXAdqKQdPNonG1sJtsH8s3uov1guRZYOLlmG42+WyVKm d/LhdQY9TktlJtM58tPHadOPF51MAzuweMEl6h/RiX7t+z41kLDrInMNRCVxbTP9BiHn OvirTAC+Lum1cyHCdOEQEnv4JvlpkJLjTW3IPOFBchPoqihF1JNa46oKwI8hlQAd3/tw 9F1RGqyffrKfHiKvUH9YvUrFInp1Xv6tZk8HAL52O5XC4DLgsdfCon9gxnmSEG52tpxP BA+5spL6iOv98/FIBesgm+zdjbZ02Dz5QaH7L+AzxaWZBertPdZy43N46Sd3MBL/YhaF DQ2A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:subject:message-id:date:from:in-reply-to :references:mime-version:dkim-signature; bh=EmOXlCPF2PKnBhpQ/luPJrSUkqjOxGD13NDVBnopNTk=; b=vrjhKKfgR0+mzlLM4LGmbO4zkFXgCqDnBtYesheEkwzAzCvWgnay2wTBomiTyhrm/S 0jJMHrtEs/YQ8xtj3zzOyjsPNy/0QD1Ng/DxWF/4v1WgVej0Kx6euKYeFmmgGdWTxlK7 FJTBmo/97m7lsET8lVX3J155BOyZUoJlwSPcurUugfgr/5lLMn9LMvxqAM7XsxqHfqoH 6w1EfcUXnh7uVNXfB+lAcnrdPUrdhqKKBVC00I0wfDMkzziFqO6rg537zeSIm4gHaNMc r0FOCpW5bftBu4Ytl2q5hkKhb1QjWwZv/5/WqsjI5Inyewsfd2aMlGRFjFn4tuj/EpmB ro3Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=oDeMmnlC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id q3-20020a50c343000000b00435dde2e294si5371408edb.124.2022.06.29.03.41.25; Wed, 29 Jun 2022 03:41:51 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=oDeMmnlC; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233025AbiF2Js0 (ORCPT + 99 others); Wed, 29 Jun 2022 05:48:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232989AbiF2JrM (ORCPT ); Wed, 29 Jun 2022 05:47:12 -0400 Received: from mail-yb1-xb2f.google.com (mail-yb1-xb2f.google.com [IPv6:2607:f8b0:4864:20::b2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62EE13D1DB; Wed, 29 Jun 2022 02:47:04 -0700 (PDT) Received: by mail-yb1-xb2f.google.com with SMTP id l11so26905078ybu.13; Wed, 29 Jun 2022 02:47:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EmOXlCPF2PKnBhpQ/luPJrSUkqjOxGD13NDVBnopNTk=; b=oDeMmnlCMTQvwXgm78D0pQRHhja+Ivd+N2hnel6/zhLoaRW5etlOls2REHUUBBbxiU 6l5jO+KyaLfcVkIx9mK5+THqtbCE14MXYjrmFL3sq/H+6dwhLMQO80vCeAz+zoyQ6tD4 /sWVN2VSVQiH58CXv/s/btxvwH9NpB+wLdHCiYrGdZSp1lqQHEe94WrDw6VCsh/tiS7K NipsDv97v242DKFzN3XNuoV1K7QUj6cBVQ6l3X+zme3htAyNlxEQ1M0ZiBiezEgSY5kH I2NkpkIjtahsqUm+/nZluwhgZxbvHL7ojm2Waao7yrYgQ7tZmB7WJKTeQ2RkU+nrkOtf Fcpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=EmOXlCPF2PKnBhpQ/luPJrSUkqjOxGD13NDVBnopNTk=; b=mEmVMWfrJlomOm5nVbd/vyNgJbv6FhC1fgEmrGzCFHyiGgVhLUye642z3x21X5H10U sZDO4UdjAP8In/iSjLxZyNG92tsPExX2Rifhh0Fwej0ve0qq5Wh4OhXgBK72m7LMr+4t Om5JeRxanN9pfmWp6xnQzeUeLwYXDlzQzOPwmmh6sMN2qfDO/XLm3DhtuhDPTjcfOLwO L/Rp+X5Jvx2DjT+detlAbcMQGHL2Au7DsgFWgRnl9wZ6+Y2EH4KLixN72LQG1GGM5l3/ EmxZowcX7VS0MxTenqitrBmmzKWshaZipAGqCMoLYwpNbiOvAgtL3ItNt3FX3AEYTf1u 2iLA== X-Gm-Message-State: AJIora8QpoDmEAt8Wn/5cVyg5sq1oyZ+YrgFdfIV7tbVxZXHTZB8mX33 CI2LmQb3GYJIzrULqbk1wVtevqig2Vp8mdjcMpALsaKsyTmq+zIQlto= X-Received: by 2002:a25:3383:0:b0:66b:6205:1583 with SMTP id z125-20020a253383000000b0066b62051583mr2289015ybz.387.1656496023486; Wed, 29 Jun 2022 02:47:03 -0700 (PDT) MIME-Version: 1.0 References: <20220629021304.21725-1-chunfeng.yun@mediatek.com> In-Reply-To: <20220629021304.21725-1-chunfeng.yun@mediatek.com> From: Ruslan Bilovol Date: Wed, 29 Jun 2022 12:46:51 +0300 Message-ID: Subject: Re: [PATCH v2] usb: gadget: f_uac1: add interface association descriptor To: Chunfeng Yun Cc: Felipe Balbi , Greg Kroah-Hartman , Matthias Brugger , Pavel Hofman , Julian Scheel , Yunhao Tian , xin lin , Linux USB , linux-kernel@vger.kernel.org, linux-arm-kernel , linux-mediatek@lists.infradead.org Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 29, 2022 at 5:13 AM Chunfeng Yun wrote: > > From: xin lin > > When we want to use a composite device that supports UVC, UAC1 and > ADB at the same time, encounter that UAC1 can't work when connected > to windows 10 system. > From the online documents of microsoft, "overview of enumeration of > interface collections on usb composite devices", it recommends that > vendors use IADs (interface association descriptor) to define > interface collections. > After addding IAD, we can fix the issue. It is incorrect to add Interface Association Descriptor to the UAC1 function. The UAC1 specification was developed much earlier than IAD was invented, and it implements this functionality in another way - by describing number of associated interfaces and interface numbers on Class-Specific AC Interface Descriptor level; see *bInCollection* and *baInterfaceNr* fields of UAC1 Class-Specific AC Interface Header Descriptor in 4.3.2 section of UAC1 specification. This is already implemented in f_uac1.c (see where *bInCollection* and *baInterfaceNr* are updated), along with support of dynamic capture/playback endpoints enablement. Adding IAD to the UAC1 driver is duplicating that functionality and isn't supported by UAC1 spec. On the other hand, the USB orgcommittee switched the approach of interface collection definition from a class-specific descriptors level to IAD in the UAC2 spec. So why not use UAC2 function for the same purpose, it already has IAD implemented and is supported by Win10? Thanks, Ruslan > > Signed-off-by: xin lin > Signed-off-by: Chunfeng Yun > --- > v2: modify commit log suggested by Greg > --- > drivers/usb/gadget/function/f_uac1.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c > index 6f0e1d803dc2..8390207bc513 100644 > --- a/drivers/usb/gadget/function/f_uac1.c > +++ b/drivers/usb/gadget/function/f_uac1.c > @@ -71,6 +71,17 @@ static inline struct f_uac1_opts *g_audio_to_uac1_opts(struct g_audio *audio) > * ALSA_Playback -> IT_3 -> OT_4 -> USB-IN > */ > > +static struct usb_interface_assoc_descriptor iad_desc = { > + .bLength = sizeof(iad_desc), > + .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION, > + > + .bFirstInterface = 0, > + .bInterfaceCount = 3, > + .bFunctionClass = USB_CLASS_AUDIO, > + .bFunctionSubClass = 0, > + .bFunctionProtocol = UAC_VERSION_1, > +}; > + > /* B.3.1 Standard AC Interface Descriptor */ > static struct usb_interface_descriptor ac_interface_desc = { > .bLength = USB_DT_INTERFACE_SIZE, > @@ -259,6 +270,7 @@ static struct uac_iso_endpoint_descriptor as_iso_in_desc = { > }; > > static struct usb_descriptor_header *f_audio_desc[] = { > + (struct usb_descriptor_header *)&iad_desc, > (struct usb_descriptor_header *)&ac_interface_desc, > (struct usb_descriptor_header *)&ac_header_desc, > > @@ -293,6 +305,7 @@ static struct usb_descriptor_header *f_audio_desc[] = { > }; > > enum { > + STR_ASSOC, > STR_AC_IF, > STR_USB_OUT_IT, > STR_USB_OUT_IT_CH_NAMES, > @@ -310,6 +323,7 @@ enum { > > static struct usb_string strings_uac1[] = { > /* [STR_AC_IF].s = DYNAMIC, */ > + [STR_ASSOC].s = "Source/Sink", > [STR_USB_OUT_IT].s = "Playback Input terminal", > [STR_USB_OUT_IT_CH_NAMES].s = "Playback Channels", > [STR_IO_OUT_OT].s = "Playback Output terminal", > @@ -1058,6 +1072,7 @@ static void setup_descriptor(struct f_uac1_opts *opts) > as_out_header_desc.bTerminalLink = usb_out_it_desc.bTerminalID; > as_in_header_desc.bTerminalLink = usb_in_ot_desc.bTerminalID; > > + iad_desc.bInterfaceCount = 1; > ac_header_desc->wTotalLength = cpu_to_le16(ac_header_desc->bLength); > > if (EPIN_EN(opts)) { > @@ -1068,6 +1083,7 @@ static void setup_descriptor(struct f_uac1_opts *opts) > if (FUIN_EN(opts)) > len += in_feature_unit_desc->bLength; > ac_header_desc->wTotalLength = cpu_to_le16(len); > + iad_desc.bInterfaceCount++; > } > if (EPOUT_EN(opts)) { > u16 len = le16_to_cpu(ac_header_desc->wTotalLength); > @@ -1077,9 +1093,11 @@ static void setup_descriptor(struct f_uac1_opts *opts) > if (FUOUT_EN(opts)) > len += out_feature_unit_desc->bLength; > ac_header_desc->wTotalLength = cpu_to_le16(len); > + iad_desc.bInterfaceCount++; > } > > i = 0; > + f_audio_desc[i++] = USBDHDR(&iad_desc); > f_audio_desc[i++] = USBDHDR(&ac_interface_desc); > f_audio_desc[i++] = USBDHDR(ac_header_desc); > > @@ -1217,6 +1235,7 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) > } > } > > + iad_desc.iFunction = us[STR_ASSOC].id; > ac_interface_desc.iInterface = us[STR_AC_IF].id; > usb_out_it_desc.iTerminal = us[STR_USB_OUT_IT].id; > usb_out_it_desc.iChannelNames = us[STR_USB_OUT_IT_CH_NAMES].id; > @@ -1302,6 +1321,8 @@ static int f_audio_bind(struct usb_configuration *c, struct usb_function *f) > status = usb_interface_id(c, f); > if (status < 0) > goto err_free_fu; > + > + iad_desc.bFirstInterface = status; > ac_interface_desc.bInterfaceNumber = status; > uac1->ac_intf = status; > uac1->ac_alt = 0; > -- > 2.18.0 >