From patchwork Fri Jul 23 10:07:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Pauli Virtanen X-Patchwork-Id: 12395809 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,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 A0ADFC4338F for ; Fri, 23 Jul 2021 10:07:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 789D5608FE for ; Fri, 23 Jul 2021 10:07:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231296AbhGWJ0h (ORCPT ); Fri, 23 Jul 2021 05:26:37 -0400 Received: from meesny.iki.fi ([195.140.195.201]:50138 "EHLO meesny.iki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230008AbhGWJ0g (ORCPT ); Fri, 23 Jul 2021 05:26:36 -0400 Received: from [192.168.1.195] (91-152-122-41.elisa-laajakaista.fi [91.152.122.41]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: pav@iki.fi) by meesny.iki.fi (Postfix) with ESMTPSA id 4219220050; Fri, 23 Jul 2021 13:07:07 +0300 (EEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1627034827; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3uptbWrx95C5QIVUbKOBVRAx/tDvlkqdSapqfCHOWS0=; b=U+u24RPvh9CljIlxFC/IKhvjjFZZv2unQdmB+g1nHBQC9SDHxksbUnGbjAmbe4z9Qq+5jF CqrBpmNyQGQDXxTms5A8fL6J2Q5beRKWmi5BFpkxEY18FHUuGgR9JVe582MHH1hGeTg3vs Q+b5VR+eg/XaY8L7afLbHfJjYkXJjYk= Message-ID: Subject: [PATCH v2] Bluetooth: btusb: check conditions before enabling USB ALT 3 for WBS From: Pauli Virtanen To: linux-bluetooth Cc: Joseph Hwang , Hilda Wu , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , =?utf-8?b?TWljaGHFgiBLxJlw?= =?utf-8?b?aWXFhA==?= Date: Fri, 23 Jul 2021 13:07:07 +0300 In-Reply-To: References: User-Agent: Evolution 3.40.3 (3.40.3-1.fc34) MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1627034827; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3uptbWrx95C5QIVUbKOBVRAx/tDvlkqdSapqfCHOWS0=; b=ed2pjYjLGmUchORHnTE2ja53QQCj3ke/2dadFuWP42LLwiALLRRjPCFBD0DsWrnrWmXIZ6 5Y8oDSn7q+IC9T3qkef1XgmSqCr5hkJvqihxJgVVd6Ypqh5j6t1ZAywu2Wtgnkueq6YYWO KuX2LPKHa3o4DITVqAYfHAW6vjKf49Y= ARC-Seal: i=1; s=meesny; d=iki.fi; t=1627034827; a=rsa-sha256; cv=none; b=AjfPLTIEkZadv+tNmDnhUtScjVhjbxsZ4ZRwtr2BlqqRhjBwF5gonYqhjGas5djHUSSTar DwTeqUrq01NwTfXUf06SIY/BjAbBETZSI1benYVocGOxuds0rtabvb1P75ZEQ8Jlp4JDf4 E0x90HBCR+TGNqwb02E1Oye+y/RiI4c= ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=pav@iki.fi smtp.mailfrom=pav@iki.fi Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org 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. Some adapters with larger MTU were also reported to have problems with ALT 3. Add a flag and check it and MTU before selecting ALT 3, falling back to ALT 1. Enable the flag for Realtek, restoring the previous behavior for non-Realtek devices. Tested with USB adapters (mtu<72, no/garbled sound with ALT3, ALT1 works) BCM20702A1 0b05:17cb, CSR8510A10 0a12:0001, and (mtu>=72, ALT3 works) RTL8761BU 0bda:8771, Intel AX200 8087:0029 (after disabling ALT6). Also got reports for (mtu>=72, ALT 3 reported to produce bad audio) Intel 8087:0a2b. Signed-off-by: Pauli Virtanen Fixes: e848dbd364ac ("Bluetooth: btusb: Add support USB ALT 3 for WBS") Tested-by: Michał Kępień --- Changes in v2: - Explain magic number 72 in a comment; didn't add the table for them, because it's not used elsewhere and we need just one number from it. - Add flag for ALT3 support, restoring the behavior for non-Realtek devices the same as before e848dbd364ac, due to the problems reported on an Intel adapter. Don't have the device myself. drivers/bluetooth/btusb.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index 6d23308119d1..5cec719f6cba 100644 --- a/drivers/bluetooth/btusb.c +++ b/drivers/bluetooth/btusb.c @@ -516,6 +516,7 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = { #define BTUSB_HW_RESET_ACTIVE 12 #define BTUSB_TX_WAIT_VND_EVT 13 #define BTUSB_WAKEUP_DISABLE 14 +#define BTUSB_ALT3_OK_FOR_WBS 15 struct btusb_data { struct hci_dev *hdev; @@ -1748,16 +1749,20 @@ static void btusb_work(struct work_struct *work) /* Bluetooth USB spec recommends alt 6 (63 bytes), but * many adapters do not support it. Alt 1 appears to * work for all adapters that do not have alt 6, and - * which work with WBS at all. + * which work with WBS at all. Some devices prefer + * alt 3 (HCI payload >= 60 Bytes let air packet + * data satisfy 60 bytes), requiring + * MTU >= 3 (packets) * 25 (size) - 3 (headers) = 72 + * see also Core spec 5, vol 4, B 2.1.1 & Table 2.1. */ - new_alts = btusb_find_altsetting(data, 6) ? 6 : 1; - /* 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. - */ - if (new_alts == 1 && btusb_find_altsetting(data, 3)) + if (btusb_find_altsetting(data, 6)) + new_alts = 6; + else if (test_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags) && + hdev->sco_mtu >= 72 && + btusb_find_altsetting(data, 3)) new_alts = 3; + else + new_alts = 1; } if (btusb_switch_alt_setting(hdev, new_alts) < 0) @@ -4733,6 +4738,7 @@ static int btusb_probe(struct usb_interface *intf, * (DEVICE_REMOTE_WAKEUP) */ set_bit(BTUSB_WAKEUP_DISABLE, &data->flags); + set_bit(BTUSB_ALT3_OK_FOR_WBS, &data->flags); } if (!reset)