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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D1C68C63697 for ; Thu, 26 Nov 2020 13:44:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 739A021D40 for ; Thu, 26 Nov 2020 13:44:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ivitera.com header.i=@ivitera.com header.b="ob5K5keW"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ivitera.com header.i=@ivitera.com header.b="ob5K5keW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390289AbgKZNoc (ORCPT ); Thu, 26 Nov 2020 08:44:32 -0500 Received: from cable.insite.cz ([84.242.75.189]:53989 "EHLO cable.insite.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390653AbgKZNoX (ORCPT ); Thu, 26 Nov 2020 08:44:23 -0500 Received: from localhost (localhost [127.0.0.1]) by cable.insite.cz (Postfix) with ESMTP id 8BC0AA9D31F71; Thu, 26 Nov 2020 14:44:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ivitera.com; s=mail; t=1606398257; bh=gQ+shCm6MCA8w2n5q0BWlcK9cbCQrq8coXa9TWHd4qw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=ob5K5keWjEYdZHCqI8r4ZChoLjl+X8HVGKHCshyxuMU6Y+Dobus/9vR1m0NLEdChh AnHiOzAyXUiSlKiiVijOgTS4jWj+up5iHH7/bZAqD3zi0fMddiB4NyxOByPgkniyvX Lfse9AY1ytwfxk71uyeDOmbCToNkdMZlwaAKhaFQ= Received: from cable.insite.cz ([84.242.75.189]) by localhost (server.insite.cz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id U97XVNLIVsWH; Thu, 26 Nov 2020 14:44:17 +0100 (CET) Received: from [192.168.100.21] (unknown [192.168.100.21]) (Authenticated sender: pavel) by cable.insite.cz (Postfix) with ESMTPSA id 6236DA9D31F75; Thu, 26 Nov 2020 14:44:17 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=ivitera.com; s=mail; t=1606398257; bh=gQ+shCm6MCA8w2n5q0BWlcK9cbCQrq8coXa9TWHd4qw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=ob5K5keWjEYdZHCqI8r4ZChoLjl+X8HVGKHCshyxuMU6Y+Dobus/9vR1m0NLEdChh AnHiOzAyXUiSlKiiVijOgTS4jWj+up5iHH7/bZAqD3zi0fMddiB4NyxOByPgkniyvX Lfse9AY1ytwfxk71uyeDOmbCToNkdMZlwaAKhaFQ= Subject: Re: [PATCH 0/3] UAC2 Gadget: feedback endpoint support To: Jerome Brunet , Ruslan Bilovol , Glenn Schmottlach Cc: Peter Chen , "balbi@kernel.org" , "linux-usb@vger.kernel.org" References: <1604794711-8661-1-git-send-email-ruslan.bilovol@gmail.com> <20201111092941.GJ14896@b29397-desktop> <1jblfk8di1.fsf@starbuckisacylon.baylibre.com> From: Pavel Hofman Message-ID: <8bf995b1-7b95-4c79-fbe8-275f29716c0e@ivitera.com> Date: Thu, 26 Nov 2020 14:44:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1jblfk8di1.fsf@starbuckisacylon.baylibre.com> Content-Type: text/plain; charset=iso-8859-2; format=flowed Content-Language: cs-CZ Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Dne 26. 11. 20 v 14:16 Jerome Brunet napsal(a): > >> Maximum data rates that I used were (AFAIR) 8 channel 192kHz/32bit, >> but there is another issue with high data rate if someone uses so many >> channels, very high sampling frequency or sample size that data can't >> fit into allowed (by USB spec) max packet size of endpoint. In this case >> need to decrease bInterval of endpoint. Should anyone test the patches with RPi4 dwc2 as the gadget, please note the recently accepted patch https://patchwork.kernel.org/project/linux-usb/patch/e9e7d070-593c-122f-3a5c-2435bb147ab2@ivitera.com/ which allows using full 1024 bytes maxpacketsize on EP OUT. It is not an enumeration issue, but the old (= existing) RX FIFO size drops data with packet sizes above 960 bytes. Thanks a lot for the great work. Best regards, Pavel.