From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Sakamoto Subject: Re: [PATCH 10/39] firewire-lib: Add transfer delay to synchronized duplex streams Date: Mon, 10 Mar 2014 22:43:26 +0900 Message-ID: <531DC17E.7020400@sakamocchi.jp> References: <5316963F.1000206@sakamocchi.jp> <1394016507-15761-1-git-send-email-o-takashi@sakamocchi.jp> <1394016507-15761-11-git-send-email-o-takashi@sakamocchi.jp> <531CD97A.6040507@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp302.phy.lolipop.jp (smtp302.phy.lolipop.jp [210.157.22.85]) by alsa0.perex.cz (Postfix) with ESMTP id 683DC2650EE for ; Mon, 10 Mar 2014 14:43:32 +0100 (CET) In-Reply-To: <531CD97A.6040507@ladisch.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Clemens Ladisch Cc: tiwai@suse.de, alsa-devel@alsa-project.org, ffado-devel@lists.sf.net List-Id: alsa-devel@alsa-project.org (mar 10 2014 06:13), Clemens Ladisch wrote: > The transfer delay is the offset between the frame in which the packet > is transmitted and the intended presentation time. This delay was > already added by the device when it sent the input packets, so we > don't need to send it again. Exactly. Adding TRANSFER_DELAY for out-packets is needless... IEC 61883-6 said: "If a function block receives a CIP, processes it and subsequently re-transmits it, then the SYT of the outgoing CIP shall be the sum of the incoming SYT and the processing delay." > The frame in which the out-packet will be sent is QUEUE_LENGTH > frames later than that of the in-packet, so we need to adjust the > SYT by that amount. (However, 48 % 16 == 0.) So basically we need to add nothing to SYT for out-packet. This patch should be removed. Thanks Takashi Sakamoto o-takashi@sakamocchi.jp