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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 554BEC34026 for ; Tue, 18 Feb 2020 19:56:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2773E24654 for ; Tue, 18 Feb 2020 19:56:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582055812; bh=BTW1v+4nfXPSeDpRwVg1EwiHze1urAfXSzUxaB5TdFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NnqzNJNHqLZWQKOy9IZ8MC0xuAzIyC2wCDiAp5V7f3AJwg2EJpiaiCJujDlyDWZ1F C2CkiETZr0UcepQ8dJq4e2eNZOcpWUXEzEz+w+q9bs4uKs2EHaMQNbGBvvztfH9DLA oUjhjgDa2HGhNnFkrF5GUM+V/FuSl8iKj56MnYM8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727656AbgBRT4v (ORCPT ); Tue, 18 Feb 2020 14:56:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:33986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727648AbgBRT4u (ORCPT ); Tue, 18 Feb 2020 14:56:50 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9BA7924654; Tue, 18 Feb 2020 19:56:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582055810; bh=BTW1v+4nfXPSeDpRwVg1EwiHze1urAfXSzUxaB5TdFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GvNZrZ5HcQWJjLApUqWxqswRtdlLOE93JNlCK/Gn4pjSsIOM/vSgfJSzV/oDAnDfD rc8Xzy2EwNn392DpTBq0CcLL64Gm7dPYYnNWUE3s9PLsdihUBnr/iD+hfmpsONVctH Dii6gqp2RonUM/ZxIfazFAc6fbPRipdKAjVtxtdA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai Subject: [PATCH 4.19 04/38] ALSA: usb-audio: Fix UAC2/3 effect unit parsing Date: Tue, 18 Feb 2020 20:54:50 +0100 Message-Id: <20200218190419.049074484@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200218190418.536430858@linuxfoundation.org> References: <20200218190418.536430858@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit d75a170fd848f037a1e28893ad10be7a4c51f8a6 upstream. We've got a regression report about M-Audio Fast Track C400 device, and the git bisection resulted in the commit e0ccdef92653 ("ALSA: usb-audio: Clean up check_input_term()"). This commit was about the rewrite of the input terminal parser, and it's not too obvious from the change what really broke. The answer is: it's the interpretation of UAC2/3 effect units. In the original code, UAC2 effect unit is as if through UAC1 processing unit because both UAC1 PU and UAC2/3 EU share the same number (0x07). The old code went through a complex switch-case fallthrough, finally bailing out in the middle: if (protocol == UAC_VERSION_2 && hdr[2] == UAC2_EFFECT_UNIT) { /* UAC2/UAC1 unit IDs overlap here in an * uncompatible way. Ignore this unit for now. */ return 0; } ... and this special handling was missing in the new code; the new code treats UAC2/3 effect unit as if it were equivalent with the processing unit. Actually, the old code was too confusing. The effect unit has an incompatible unit description with the processing unit, so we shouldn't have dealt with EU in the same way. This patch addresses the regression by changing the effect unit handling to the own parser function. The own parser function makes the clear distinct with PU, so it improves the readability, too. The EU parser just sets the type and the id like the old kernels. Once when the proper effect unit support is added, we can revisit this parser function, but for now, let's keep this simple setup as is. Fixes: e0ccdef92653 ("ALSA: usb-audio: Clean up check_input_term()") Cc: BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206147 Link: https://lore.kernel.org/r/20200211160521.31990-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/mixer.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -912,6 +912,15 @@ static int parse_term_proc_unit(struct m return 0; } +static int parse_term_effect_unit(struct mixer_build *state, + struct usb_audio_term *term, + void *p1, int id) +{ + term->type = UAC3_EFFECT_UNIT << 16; /* virtual type */ + term->id = id; + return 0; +} + static int parse_term_uac2_clock_source(struct mixer_build *state, struct usb_audio_term *term, void *p1, int id) @@ -996,8 +1005,7 @@ static int __check_input_term(struct mix UAC3_PROCESSING_UNIT); case PTYPE(UAC_VERSION_2, UAC2_EFFECT_UNIT): case PTYPE(UAC_VERSION_3, UAC3_EFFECT_UNIT): - return parse_term_proc_unit(state, term, p1, id, - UAC3_EFFECT_UNIT); + return parse_term_effect_unit(state, term, p1, id); case PTYPE(UAC_VERSION_1, UAC1_EXTENSION_UNIT): case PTYPE(UAC_VERSION_2, UAC2_EXTENSION_UNIT_V2): case PTYPE(UAC_VERSION_3, UAC3_EXTENSION_UNIT):