From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Sakamoto Subject: Re: [RFC] [PATCH] firewire-lib: add support for AV/C deferred transaction Date: Sat, 15 Mar 2014 22:09:12 +0900 Message-ID: <532450F8.10202@sakamocchi.jp> References: <5323151D.3010706@sakamocchi.jp> <532381B7.3030903@ladisch.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp310.phy.lolipop.jp (smtp310.phy.lolipop.jp [210.157.22.78]) by alsa0.perex.cz (Postfix) with ESMTP id 4E0A126509E for ; Sat, 15 Mar 2014 14:09:19 +0100 (CET) In-Reply-To: <532381B7.3030903@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: "alsa-devel@alsa-project.org" , Stefan Richter , linux1394-devel@lists.sourceforge.net, "ffado-devel@lists.sf.net" List-Id: alsa-devel@alsa-project.org Hi Clemens, (Mar 15 2014 07:24), Clemens Ladisch wrote: > Looks OK. Thanks for your quick review. > In theory, a device that uses INTERIM is likely to need a larger timeout > than the FCP default, but as long as 125 ms works for those BeBoB devices, > increasing the timeout is not necessary. With this value and BeBoB devices which I own, I have experienced no retry/timeout. As long as I know, BeBoB based devices need much time to complete immediate/deferred transaction for changing sampling rate during streaming. In this case, immediate transactions need 150 msec or more and deferred transactions need 40/240msec or more to complete. But BeBoB driver must not change sampling rate in this case because sampling rate should not be changed during streaming. The driver should stop streaming once then change sampling rate. I suggest that we will change this value when finding devices which need more timeout. Thanks Takashi Sakamoto o-takashi@sakamocchi.jp