Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750923AbdHRF4I (ORCPT ); Fri, 18 Aug 2017 01:56:08 -0400 Received: from mail-lf0-f67.google.com ([209.85.215.67]:37709 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750709AbdHRF4G (ORCPT ); Fri, 18 Aug 2017 01:56:06 -0400 Subject: Re: [PATCH RESEND1 00/12] ALSA: vsnd: Add Xen para-virtualized frontend driver To: Takashi Sakamoto , Oleksandr Grytsov , clemens@ladisch.de Cc: alsa-devel@alsa-project.org, xen-devel@lists.xen.org, linux-kernel@vger.kernel.org, tiwai@suse.com, Oleksandr Andrushchenko References: <1502108577-8099-1-git-send-email-andr2000@gmail.com> <7e62a406-7dcd-b5c9-b2de-ea52e1d2afd0@sakamocchi.jp> From: Oleksandr Andrushchenko Message-ID: <2a2fd222-fc54-1709-bfc8-a530efc3f307@gmail.com> Date: Fri, 18 Aug 2017 08:56:01 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1292 Lines: 38 Hello, On 08/18/2017 08:43 AM, Takashi Sakamoto wrote: > On Aug 17 2017 19:05, Oleksandr Grytsov wrote: >> So, from the above we think that period elapsed event derived in the >> described >> ways may not improve latency and will complicate the system. So, for >> that >> reason we are thinking of the option 2) (Positions of actual data >> transmission >> in any serial sound interfaces of actual hardwares.) > > Please declare the way to enable stuffs on DomU to get the positions > from actual hardware. > This is what we haven't investigated yet in detail as we were mostly focusing on period elapsed approach, so we can report our findings to the community. Taking into account the fact that the backend we have is a user-space application running on top of ALSA/PulseAudio we cannot get HW pointers from actual hardware by any means (PulseAudio use-case is the most tough thing in equation) At the moment we are seeking for any advise from more experienced developers in the field on possible ways to solve the problem of Dom0/DomU synchronization. Hope, together we can identify such a way that would be accepted by the community. If you have something on your mind could you please share your thoughts? > > Regards > > Takashi Sakamoto Thank you, Oleksandr Andrushchenko