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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL 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 93196C636CA for ; Sat, 17 Jul 2021 13:35:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7228E6115B for ; Sat, 17 Jul 2021 13:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233125AbhGQNiI (ORCPT ); Sat, 17 Jul 2021 09:38:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229746AbhGQNiH (ORCPT ); Sat, 17 Jul 2021 09:38:07 -0400 Received: from mail-ua1-x92e.google.com (mail-ua1-x92e.google.com [IPv6:2607:f8b0:4864:20::92e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CC60C06175F for ; Sat, 17 Jul 2021 06:35:10 -0700 (PDT) Received: by mail-ua1-x92e.google.com with SMTP id n61so4778702uan.2 for ; Sat, 17 Jul 2021 06:35:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=prMbdjZsxOgJbK6uUoKMbaLY4SrWw8gmg6+Jlty6xBY=; b=GO4jrEsNa4mBOxumLQ7ESBVxz427YiDmZDUOuX/1sx9BclFjQw0SeRYRSeQoG96PIW +xl+WmG6ZoHAfCA2dxd8Bh/yfaSZGnZ/swzFNx2Zrr2OX5AHM6DjlDprZaThJA8NwRbY WqJSCkLPbLZeB9okQ5zKEzV2VpP9VuPDilMBnBXHyra/Oy0x3WJQoL0lvaUiHMD4oEbD LER0L7hO1wnP0pcNhxol1tjN0D64olfWfxaJiz3ZIeFAe+O4cWkxdpPnKRk5DrasQnky Zg3TEhKLdIDlxHzAJGAQmv7ZghWzQ+dObkCNge8HzJ1MbPmxehOpQ2PV6BLUaxPzAHyt l4Bw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=prMbdjZsxOgJbK6uUoKMbaLY4SrWw8gmg6+Jlty6xBY=; b=VpDyjpDG8mFyNYNXpiSewVpleTnaHhi68BIV91dXfyZI17NcN2vN8zAb7TB1/ZFnZt hu6SX35BsHLDSlqpxx8Su3rE4mhiXVPfj9WCAvLF2RiAegIE+jg+WyULK1IY55EIoRud 2A+SRODfrrkG2wukgDrB590QHzuRE/XTG4K8Kpm2ihC5Pzcttu9RuJr5iHZzdDjU/X2d paZZtjqpgey6Ts6rku9r/mzn2pgRlPTu0WthvzeTjaX26BX5xbigkCg2rS008QCaLr9F hkKUp1MqmXO4Bmm8v/9gaPkIveZZ0VYlvzETRIGnIfJtOXfFNArJf5kOpjkWJgRH9sqY 9Q8Q== X-Gm-Message-State: AOAM53299pHJjFnX04UD+Jl4yw0BDAI4BkR9TIuLcRjiD9zIm2mDkalN 4wsY4K73qS7L8kPgCerkEsQ93OmGHHAvxc5PE8TJMA== X-Google-Smtp-Source: ABdhPJwsRKiCBzAwhhdvQYIouAsViI06GDp+fGSjLxy3u7z669i3QV2p0ex+LvNCfG5qt49+jnmlgGKBhVTJzvqFeHY= X-Received: by 2002:ab0:7c67:: with SMTP id h7mr18894262uax.61.1626528909223; Sat, 17 Jul 2021 06:35:09 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Joseph Hwang Date: Sat, 17 Jul 2021 21:34:57 +0800 Message-ID: Subject: Re: [PATCH] Bluetooth: btusb: check SCO MTU before enabling USB ALT 3 for WBS To: Pauli Virtanen Cc: linux-bluetooth , Hilda Wu Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org It looks reasonable to check sco_mtu. My suggestion is to use hci_packet_size_usb_alt[3] instead of the magic number 72. Thanks, Joseph On Sat, Jul 17, 2021 at 1:58 AM Pauli Virtanen wrote: > > Some USB BT adapters don't satisfy the MTU requirement mentioned in > commit e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS") > and have ALT 3 setting that produces no/garbled audio. Check that the MTU > condition is satisfied, and fall back to ALT 1 if not. > > Tested with USB adapters (mtu<72, produce sound only with ALT1) > BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3) > RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling ALT6). > > Signed-off-by: Pauli Virtanen > --- > drivers/bluetooth/btusb.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c > index a9855a2dd561..3ee66e415c4d 100644 > --- a/drivers/bluetooth/btusb.c > +++ b/drivers/bluetooth/btusb.c > @@ -1763,9 +1763,11 @@ static void btusb_work(struct work_struct *work) > /* Because mSBC frames do not need to be aligned to the > * SCO packet boundary. If support the Alt 3, use the > * Alt 3 for HCI payload >= 60 Bytes let air packet > - * data satisfy 60 bytes. > + * data satisfy 60 bytes. USB Alt 3 support also needs > + * HFP transparent MTU >= 72 Bytes. > */ > - if (new_alts == 1 && btusb_find_altsetting(data, 3)) > + if (new_alts == 1 && hdev->sco_mtu >= 72 && > + btusb_find_altsetting(data, 3)) > new_alts = 3; > } > > -- > 2.31.1 > > -- Joseph Shyh-In Hwang Email: josephsih@google.com