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=-5.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 52BC6C33CAC for ; Thu, 6 Feb 2020 15:41:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2316821775 for ; Thu, 6 Feb 2020 15:41:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581003690; bh=getx8jCYY9DMV357owsT86p5lyapzeSeUE9DgzNKfRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=jvV90sA70kpGsJfA6H0lR3j34ceu0MTfck9AwBNfu7vn8T9UQFlP5g2j89sTEW+BK 8V8CXjqcF53i8D7SY5U1gSckRo5QswH7/neU/vLC8MzqxFDz8hjEL0CffwESat/ea5 f7hMO1d2w9k/MvGJf8gokUya+QPtZKJnhXXPO1MA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727473AbgBFPl3 (ORCPT ); Thu, 6 Feb 2020 10:41:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:60014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbgBFPl2 (ORCPT ); Thu, 6 Feb 2020 10:41:28 -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 8DD6E21775; Thu, 6 Feb 2020 15:41:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581003688; bh=getx8jCYY9DMV357owsT86p5lyapzeSeUE9DgzNKfRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=slvE/wQhSYuEnD+qD2E6XgyE8oFXlIiqCiYJ5mldAEV7fgq00+XJPX8esbQ6SAynD pD2dGpsI3PxGMvm2kUjqBhO0h0XvKjs2/Fg5t8OqsxGQF2caXtx3QkJzG6xJmsDs7V PLRfdz19tkovL+DBJW+qfPqg5Ay4kY6Tot8VXe5s= Date: Thu, 6 Feb 2020 16:41:25 +0100 From: Greg KH To: Pavel Hofman Cc: linux-usb@vger.kernel.org Subject: Re: usb:gadget:f_uac2: EP OUT is adaptive instead of async Message-ID: <20200206154125.GA3752902@kroah.com> References: <4bd36708-0ade-fbd7-5eec-5b8df7b3f2ee@ivitera.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4bd36708-0ade-fbd7-5eec-5b8df7b3f2ee@ivitera.com> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Feb 06, 2020 at 02:22:47PM +0100, Pavel Hofman wrote: > Hi, > > The existing UAC2 implementation presents itself as asynchronous > USB_ENDPOINT_SYNC_ASYNC https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/function/f_uac2.c#L276 > + https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/function/f_uac2.c#L285 > . > > However: > 1) The function does not define any feedback endpoint > > 2) IMO in reality it is adaptive - the g_audio capture device accepts any > data passed by the USB host, the USB host is the one which defines the data > pace. > > While Linux and reportedly OSX accept the async EP OUT without explicit > feedback EP IN, Windows does not. > > Simply changing USB_ENDPOINT_SYNC_ASYNC to USB_ENDPOINT_SYNC_ADAPTIVE for > the FS and HS output endpoints fixes the windows problem and IMO corrects > the config to reflect real function. > > There are multiple projects underway adding the async feedback EP, but in > the meantime I think the .bmAttributes information should be changed as > above, making the device usable in Windows for everyone. > > Thanks a lot for considering. Patches work best, can you create them and test and then submit? thanks, greg k-h