linux-kernel - Re: [PATCH 2/2] ASoC: Codec: wm8962: declare ALC Coefficients as 4 separate registers

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Message-ID: <20151006110114.GN12635@sirena.org.uk>
Date:	Tue, 6 Oct 2015 12:01:14 +0100
From:	Mark Brown <broonie@...nel.org>
To:	Jiada Wang <jiada_wang@...tor.com>
Cc:	lgirdwood@...il.com, perex@...ex.cz, tiwai@...e.com,
	patches@...nsource.wolfsonmicro.com, alsa-devel@...a-project.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] ASoC: Codec: wm8962: declare ALC Coefficients as 4
 separate registers

On Tue, Oct 06, 2015 at 04:06:55PM +0900, Jiada Wang wrote:

> As ALC2 register is volatile, declare it as one of ALC Coefficients
> register together with other non-volatile registers will cause issue,
> in case wm8962 has enter suspend mode, and cache_only flag is set,
> any attempt to read from ALC2 will fail.

> Instead of declaring one ALC Coefficients register which contains
> ALC1 ~ ALC3 and Noise Gate, this patch declares 4 separate registers,
> so that regmap can handle these registers differently based on their
> classification.

I don't understand this commit log.  Why does regmap care how these
registers are presented to userspace, and how does splitting the
controls up address the problem with one of the registers being volatile?
Surely that register still has the same problem?

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