linux-kernel - Re: [PATCH v7] ASoC: tas2552: Support TI TAS2552 Amplifier

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Date:	Thu, 17 Jul 2014 17:58:16 +0100
From:	Mark Brown <broonie@...nel.org>
To:	Dan Murphy <dmurphy@...com>
Cc:	linux-sound@...r.kernel.org, linux-kernel@...r.kernel.org,
	alsa-devel@...a-project.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v7] ASoC: tas2552: Support TI TAS2552 Amplifier

On Mon, Jul 14, 2014 at 03:10:45PM -0500, Dan Murphy wrote:

There's a few smallish issues below but this is basically good so I've
applied it, please send incremental fixed for the things below.

> +	/* Turn on Class D amplifier */
> +	snd_soc_update_bits(codec, TAS2552_CFG_2, TAS2552_CLASSD_EN_MASK,
> +						TAS2552_CLASSD_EN);
> +

Why is this being done in hw_params() and not using DAPM?

> +static int tas2552_runtime_suspend(struct device *dev)
> +{
> +	struct tas2552_data *tas2552 = dev_get_drvdata(dev);
> +
> +	tas2552_sw_shutdown(tas2552, 0);
> +
> +	if (tas2552->enable_gpio)
> +		gpiod_set_value(tas2552->enable_gpio, 0);
> +
> +	regcache_cache_only(tas2552->regmap, true);
> +	regcache_mark_dirty(tas2552->regmap);

It's better to do the GPIO set after making the device cache only in
order to be sure nothing can come in and try to use the register map
between the two.

> +static void tas2552_shutdown(struct snd_pcm_substream *substream,
> +			   struct snd_soc_dai *dai)
> +{
> +	struct snd_soc_codec *codec = dai->codec;
> +
> +	snd_soc_update_bits(codec, TAS2552_CFG_2, TAS2552_PLL_ENABLE, 0);
> +}

I'd also expect the PLL power to be managed via DAPM.

> +	ret = pm_runtime_get_sync(codec->dev);
> +	if (ret < 0) {
> +		dev_err(codec->dev, "Enabling device failed: %d\n",
> +			ret);
> +		goto probe_fail;
> +	}

There's no matching put for this in remove().

> +	snd_soc_write(codec, TAS2552_CFG_2, TAS2552_CLASSD_EN |
> +				  TAS2552_BOOST_EN | TAS2552_APT_EN |
> +				  TAS2552_LIM_EN);
> +	return 0;

The class D is still being enabled here.

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