From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: [PATCH 02/10] ALSA: dice: wait for ensuring phase lock Date: Sat, 12 Dec 2015 12:42:18 +0100 Message-ID: <566C081A.1000804@ladisch.de> References: <1449889570-26641-1-git-send-email-o-takashi@sakamocchi.jp> <1449889570-26641-3-git-send-email-o-takashi@sakamocchi.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from dehamd003.servertools24.de (dehamd003.servertools24.de [31.47.254.18]) by alsa0.perex.cz (Postfix) with ESMTP id 9418F2606E6 for ; Sat, 12 Dec 2015 12:42:40 +0100 (CET) In-Reply-To: <1449889570-26641-3-git-send-email-o-takashi@sakamocchi.jp> 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: Takashi Sakamoto , tiwai@suse.de Cc: alsa-devel@alsa-project.org, ffado-devel@lists.sf.net List-Id: alsa-devel@alsa-project.org Takashi Sakamoto wrote: > Some users have reported that their Dice based models generate packet > discontinuity at the beginning of streaming. When standing on an > assumption that the value of SYT field in transferred AMDTP packet comes > from phase lock circuit, this comes from phase unlocking with current > clock source. Just waiting for dice notification is not enough to prevent > from packet discontinuity. > > This commit checks the register of phase lock after clock state change for > this purpose. Is this patch actually known to help? This discontinuity could also come from an unexpected initial DBC value. I think it would be a good idea to unconditionally enable CIP_SKIP_INIT_DBC_CHECK for all devices. Regards, Clemens