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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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_AGENT_GIT autolearn=unavailable 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 DD0E9C43619 for ; Mon, 15 Mar 2021 14:25:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5A046509B for ; Mon, 15 Mar 2021 14:25:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237842AbhCOOWJ (ORCPT ); Mon, 15 Mar 2021 10:22:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:35186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232910AbhCOOAJ (ORCPT ); Mon, 15 Mar 2021 10:00:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5D41B64FA9; Mon, 15 Mar 2021 13:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816794; bh=LbGxFmVQStseu6Vfh+ceI5PzXi6WjKjSvnUMw8vGrkI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CmvhO7bAvPeleKnJRW9jsomJj536l45l9u2opPTK/tHxT7DctKKccFD0DvrV4qXt/ D2w0HplYLeZQ8WJ64GICiPx8aTwZTkw+AV7HgtTFwyVQHnG+VB6+vTDv6zz9V2wNhs J1qB1HOhWwSTqHPzWkk76HWT85foRb0VdRUshPhI= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Chen , Ruslan Bilovol Subject: [PATCH 4.19 072/120] usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot Date: Mon, 15 Mar 2021 14:57:03 +0100 Message-Id: <20210315135722.337953324@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135720.002213995@linuxfoundation.org> References: <20210315135720.002213995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Ruslan Bilovol commit 789ea77310f0200c84002884ffd628e2baf3ad8a upstream. As per UAC2 Audio Data Formats spec (2.3.1.1 USB Packets), if the sampling rate is a constant, the allowable variation of number of audio slots per virtual frame is +/- 1 audio slot. It means that endpoint should be able to accept/send +1 audio slot. Previous endpoint max_packet_size calculation code was adding sometimes +1 audio slot due to DIV_ROUND_UP behaviour which was rounding up to closest integer. However this doesn't work if the numbers are divisible. It had no any impact with Linux hosts which ignore this issue, but in case of more strict Windows it caused rejected enumeration Thus always add +1 audio slot to endpoint's max packet size Fixes: 913e4a90b6f9 ("usb: gadget: f_uac2: finalize wMaxPacketSize according to bandwidth") Cc: Peter Chen Cc: #v4.3+ Signed-off-by: Ruslan Bilovol Link: https://lore.kernel.org/r/1614599375-8803-2-git-send-email-ruslan.bilovol@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_uac2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/usb/gadget/function/f_uac2.c +++ b/drivers/usb/gadget/function/f_uac2.c @@ -482,7 +482,7 @@ static int set_ep_max_packet_size(const } max_size_bw = num_channels(chmask) * ssize * - DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1))); + ((srate / (factor / (1 << (ep_desc->bInterval - 1)))) + 1); ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_size_bw, max_size_ep));