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=-9.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 BF0B7C433E0 for ; Mon, 27 Jul 2020 12:21:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96F472074F for ; Mon, 27 Jul 2020 12:21:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tx7NILK7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728294AbgG0MV2 (ORCPT ); Mon, 27 Jul 2020 08:21:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728124AbgG0MV1 (ORCPT ); Mon, 27 Jul 2020 08:21:27 -0400 Received: from mail-oo1-xc41.google.com (mail-oo1-xc41.google.com [IPv6:2607:f8b0:4864:20::c41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6170C061794 for ; Mon, 27 Jul 2020 05:21:27 -0700 (PDT) Received: by mail-oo1-xc41.google.com with SMTP id z10so230110ooi.10 for ; Mon, 27 Jul 2020 05:21:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=cKl9wH3ozqqpJTIt/IjccYMf+/q0iSRZmm3fxklxSkc=; b=tx7NILK7yxaiSxHHiMoZxv3+qZNy3D2bZudvsh5Oftl/WXVc4nquDGydzcKPxm1GGr iKhryB0u248LgvHZXC4IuO00mNv+WLbrCbDzoYRKcPV7KMzh4/Q352/bifixZHAv0s76 LQAWM5+EhxeUfElmQNUC5VMMr3lOC0hBZFoCYDP9hsyWpevOo6ckBlZDe3FYptSyJm85 v/oVWqD6tiQNqxUWaFVL2RqqerFPM2av21pOT/XiO/b9t4ix54jkqSrLF+HbbfLT/Eog YgxWGlS9GqyfpyMqJ6wjDI2MTHjfu4FB0bOXpsmEZWK78DM0UWcutAWpZOuoDe0KIWJb hLzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=cKl9wH3ozqqpJTIt/IjccYMf+/q0iSRZmm3fxklxSkc=; b=pyb/Bg4mMK+TkoAi4PFaPofEhF5k/YN2M3V4HRvypj60CZg5Wybne03BxsZrlaF5RM FkzmPzWhXbm4zyJU+M8/Lomtl1cimTjg0+CoX/tobKEeSM/rwglUSgSyLyR78q3OX8Hb 9WgXQm4AUgmoMfo+rtBb3uV31xLV/uo09zB+s8FFJUe2bbCpCEFKSSJY4MaKjJaPLJAK rjTYlgT+MbvNlk8qWycPMOMWswwBTNEU8OyvU/cS4nRn8QMN1WVD79Am31r6GmucsLba zY6S7pGLMEQ566vYhY118tzKMzfuv+YOm9aq0MY+ZsOGCquKRWoOY1J09nPcOqRukT9P i6jg== X-Gm-Message-State: AOAM532mH1yApjyApbfZnb3yJkTuFogZB/tAsQlrVILizBtn+vKNjix2 3li+/N7xLm0R9YBiQe5stOwLrNasOE97CCImePHXvZX/drU= X-Google-Smtp-Source: ABdhPJw8GqRnQKT3pvzFWoc/sPGSC/01YVHyawr2eXcQR6jMH7X4lGoVNWCmmebfC0W64NWHjZVVOXFIjHJiudMUrd8= X-Received: by 2002:a4a:d62c:: with SMTP id n12mr12236306oon.38.1595852487099; Mon, 27 Jul 2020 05:21:27 -0700 (PDT) MIME-Version: 1.0 References: <79D67DF9-2A12-40DE-AFF7-4FF68193AD1C@me.com> <6194f859-aa61-90fa-043e-1df02b01bacb@ivitera.com> In-Reply-To: <6194f859-aa61-90fa-043e-1df02b01bacb@ivitera.com> From: Ruslan Bilovol Date: Mon, 27 Jul 2020 15:21:04 +0300 Message-ID: Subject: Re: usb:gadget:f_uac2: EP OUT is adaptive instead of async To: Pavel Hofman Cc: harrison conroy , Linux USB Content-Type: text/plain; charset="UTF-8" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Sat, Jul 25, 2020 at 1:24 PM Pavel Hofman wrote: > > > Dne 22. 07. 20 v 17:25 harrison conroy napsal(a): > > Hi Ruslan, > > > > I am working on a project that involves using an RPi 4 as a USB Gadget > > and we have run into the feedback endpoint issue causing Windows 10 to > > not recognize it as a USB audio device. Do you have any updates on this > > patch for the community? Any help would be greatly appreciated. > > As a temporary workaround you can change the EP OUT type from > USB_ENDPOINT_SYNC_ASYNC to USB_ENDPOINT_SYNC_ADAPTIVE. > > Or you can add implicit feedback flag to the EP IN. Win10 should handle > implicit feedback OK, unlike Win7. Unfortunately linux still requires an > explicit quirk for the implicit feedback > https://www.spinics.net/lists/alsa-devel/msg111824.html . Yet it is > still a workaround because IMO the existing EP IN is in fact not async > but adaptive, clocked by the USB frames. > There is a commit which I've sent earlier this month which is a part of Win10 enumeration solution: https://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb.git/commit/?h=next&id=a9cf8715180b18c62addbfe6f6267b8101903119 For the rest of the solution (feedback endpoint implementation) I'm refreshing patches on top of this, and expect to submit them very soon Thanks, Ruslan