From patchwork Mon Mar 15 13:51:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 401643 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=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 23DE8C43333 for ; Mon, 15 Mar 2021 13:54:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7DC064EE3 for ; Mon, 15 Mar 2021 13:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231240AbhCONyP (ORCPT ); Mon, 15 Mar 2021 09:54:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:56488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230440AbhCONxk (ORCPT ); Mon, 15 Mar 2021 09:53:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BE26864EFB; Mon, 15 Mar 2021 13:53:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816420; bh=eIQ1Dx6r4nTfUikTFLl1a1FCC6RAXUFnnPDny7KbnQQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uk2SMWcG2QuJMbAuQiX+o1BSHpVqni058AWy/siFKpb+EVnihEyHl0Llt8YzJWppl iixPErKUmoFnmF1aZwwp+WsXr+8cNN3Wb801MeR6mP63OzKK/qd7NFdGdk0WHp1zEc XhQLH1QXGiq5LmU9qFJXDtYiL2p64PzxxsrqZ0Ho= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Chen , Ruslan Bilovol Subject: [PATCH 4.4 33/75] usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot Date: Mon, 15 Mar 2021 14:51:47 +0100 Message-Id: <20210315135209.336312188@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135208.252034256@linuxfoundation.org> References: <20210315135208.252034256@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -997,7 +997,7 @@ 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));