From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] ASoC: Add Jassi Brar as Samsung maintainer Date: Sun, 26 Sep 2010 22:41:50 -0700 Message-ID: <20100927054149.GA13056@opensource.wolfsonmicro.com> References: <1285402601-10131-1-git-send-email-broonie@opensource.wolfsonmicro.com> <20100927001959.GB10638@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id DD13F24557 for ; Mon, 27 Sep 2010 07:41:31 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Kyungmin Park Cc: =?utf-8?B?7LWc7LCs7Jqw?= , alsa-devel@alsa-project.org, Jassi Brar , Jassi Brar , Liam Girdwood List-Id: alsa-devel@alsa-project.org On Mon, Sep 27, 2010 at 11:01:54AM +0900, Kyungmin Park wrote: > Yes, recent Samsung SoC supports the clock & block gating. As the > word, clock gating means enable/disable the clock and block gating > means turn on/off some peripherals blocks to reduce the power. e..g, > In case of audio, AUDIO block including I2S, AC97 and so on. It's very straightforward, yes (though in the case of AC'97 the split between CODEC and CPU is more tricky than you might at first think since by default the CPU is clock master for everything). > However codec is different. even though it can turn on/off codec, I > think it have to re-initialize to use it and it takes some times. The same is true for CPU IPs, of course. With modern CODECs this is becoming less and less of an issue - with VMID referenced CODECs there was always a lengthy delay to bring up VMID but with ground referenced, PDM and class D outputs it's becoming less and less of an issue to just power things down.