linux-kernel - Re: [alsa-devel][PATCH v2] ASoC: wm8960: Let wm8960 codec driver manage its own MCLK

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Message-ID: <20141204112512.GS7712@sirena.org.uk>
Date:	Thu, 4 Dec 2014 11:25:12 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Zidan Wang <b50113@...escale.com>
Cc:	lgirdwood@...il.com, perex@...ex.cz, tiwai@...e.de,
	lars@...afoo.de, ckeepax@...nsource.wolfsonmicro.com,
	Li.Xiubo@...escale.com, patches@...nsource.wolfsonmicro.com,
	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [alsa-devel][PATCH v2] ASoC: wm8960: Let wm8960 codec driver
 manage its own MCLK

On Thu, Dec 04, 2014 at 04:23:45PM +0800, Zidan Wang wrote:

> If we use PLL to generate sysclk, wm8960_set_dai_pll() will enable PLL. But
> PLL doesn't power down after using codec. So power down PLL in suspend().

That would be a bug in the machine driver, the machine driver should be
disabling the PLL when it suspends since the startup and shutdown of the
PLL need to be coordinated with the input clocks.  Besides, if we were
doing this in the CODEC driver then as I said last time the PLL needs to
be restored on resume since the machine driver should be able to expect
that settings it has made are preserved (eg, if it sets things up on
init).

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