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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F1289C433F5 for ; Fri, 10 Sep 2021 05:09:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 57F2260FE3 for ; Fri, 10 Sep 2021 05:09:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 57F2260FE3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:41322 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mOYmZ-00029i-35 for qemu-devel@archiver.kernel.org; Fri, 10 Sep 2021 01:08:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38856) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mOYlR-00011w-SV for qemu-devel@nongnu.org; Fri, 10 Sep 2021 01:07:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26752) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mOYlP-0002Q8-KR for qemu-devel@nongnu.org; Fri, 10 Sep 2021 01:07:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631250464; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=uKWEhVbvOQYJZCxu29fgtPsjRwc3RHyqva8rpTzm2VY=; b=OnJr78tH413SzzeOUcs+s4lIsClvXULY3K0qC5JWRoeHI6AsuEf2PFDfE2+0F6SZnE1UQT 8OFxoEA85vt0sA5qxdz1ezaEWBERaMOVD45O/d7cKGmgKl45Ge9WxPDL6y/v3CJPGUnO1U wwqTOyAViMYU5RG6MhSJsaiwr7yT1eE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-255-GIndI8zhNIqMu_TgCMYtXg-1; Fri, 10 Sep 2021 01:07:43 -0400 X-MC-Unique: GIndI8zhNIqMu_TgCMYtXg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1DBDA1006AA0; Fri, 10 Sep 2021 05:07:42 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.192.91]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C79F25FCA6; Fri, 10 Sep 2021 05:07:41 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 374EF18000AA; Fri, 10 Sep 2021 07:07:40 +0200 (CEST) Date: Fri, 10 Sep 2021 07:07:40 +0200 From: Gerd Hoffmann To: Programmingkid Subject: Re: Implementing isochronous transfers in hw/hcd-ohci.c Message-ID: <20210910050740.pgdcwhe5scohepps@sirius.home.kraxel.org> References: <263FF66A-21D7-4D0D-BE37-2D44B484A1EE@gmail.com> MIME-Version: 1.0 In-Reply-To: <263FF66A-21D7-4D0D-BE37-2D44B484A1EE@gmail.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kraxel@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=kraxel@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.393, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: QEMU Developers , Howard Spoelstra Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Sep 09, 2021 at 05:06:17PM -0400, Programmingkid wrote: > Hi Gerd, > > Howard and I were talking about USB audio problems with Mac OS guests. We think the issue might be with frames being sent to the USB audio card too soon. My guess is only one frame is suppose to be transmitted every 1 millisecond. I was also reading the todo notes in the file hw/hcd-ohci.c. This is what it says: > > * TODO: > * o Isochronous transfers > * o Allocate bandwidth in frames properly > * o Disable timers when nothing needs to be done, or remove timer usage > * all together. > * o BIOS work to boot from USB storage > */ > > Do you think implementing isochronous transfers would fix the audio problems Mac OS guest are experiencing? Most likely yes, audio devices typically use iso endpints. take care, Gerd