From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751677Ab1F3N6S (ORCPT ); Thu, 30 Jun 2011 09:58:18 -0400 Received: from newsmtp5.atmel.com ([204.2.163.5]:21050 "EHLO sjogate2.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751097Ab1F3N6N (ORCPT ); Thu, 30 Jun 2011 09:58:13 -0400 Message-ID: <4E0C80B8.7030006@atmel.com> Date: Thu, 30 Jun 2011 15:57:12 +0200 From: Nicolas Ferre Organization: atmel User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fr; rv:1.9.2.18) Gecko/20110616 Lightning/1.0b2 Thunderbird/3.1.11 MIME-Version: 1.0 To: Mark Brown , alsa-devel@alsa-project.org CC: lrg@ti.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, =?ISO-8859-1?Q?Uwe_Kleine-K=F6nig?= Subject: Re: [PATCH 1/5] ASoC: wm8731: rework power management References: <1309370419-22810-1-git-send-email-nicolas.ferre@atmel.com> <20110629171148.GB10798@opensource.wolfsonmicro.com> In-Reply-To: <20110629171148.GB10798@opensource.wolfsonmicro.com> X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 29/06/2011 19:11, Mark Brown : > On Wed, Jun 29, 2011 at 08:00:15PM +0200, Nicolas Ferre wrote: > > Don't mix multiple changes into a single patch! There's no perceptible > code overlap between these so I don't understand why you've merged them, > it just makes review harder and the changelog less descriptive. Ok. >> - preserve crystal oscillator across suspend/resume sequence: >> enabled by default, it should be kept enabled on resume. > > This isn't what your code does... > >> snd_soc_write(codec, WM8731_ACTIVE, 0x0); >> - snd_soc_write(codec, WM8731_PWR, 0xffff); >> + /* standby: keep crystal oscillator enabled */ >> + snd_soc_write(codec, WM8731_PWR, 0x00df); > > This doesn't keep the crystal oscillator enabled, this forces it on in > suspend (and without looking at the datasheet it also changes way more > than the one register bit I'd expect to be changed). If the system > isn't using the oscillator then that's not good. > > I'd expect to see a change to using snd_soc_update_bits() based on your > description, or more likely something more involved. First of all, I experienced issues while not having OSC enabled during suspend/resume cycle. Am I right supposing that, if using oscillator to clock the codec, I have to keep it running during a suspend/resume cycle? Is something like this sounds like an acceptable option or we need something more sophisticated? @@ -481,7 +481,10 @@ static int wm8731_set_bias_level(struct snd_soc_codec *codec, break; case SND_SOC_BIAS_OFF: snd_soc_write(codec, WM8731_ACTIVE, 0x0); - snd_soc_write(codec, WM8731_PWR, 0xffff); + reg = 0xdf; + if (wm8731->sysclk_type == WM8731_SYSCLK_XTAL) + reg |= 1 << 0x5; + snd_soc_update_bits(codec, WM8731_PWR, 0x00ff, reg); regulator_bulk_disable(ARRAY_SIZE(wm8731->supplies), wm8731->supplies); break; And, yes, there is only 8 bits dedicated to power down control in this register. Best regards, -- Nicolas Ferre