[alsa-devel] [PATCH v2] ASoC: sun4i-i2s: move code from startup/shutdown hooks into pm_runtime hooks

[Maxime Ripard]

On Mon, Oct 15, 2018 at 08:11:41PM -0700, Vasily Khoruzhick wrote:
> startup() and shutdown() hooks are called for both substreams,
> so stopping either substream when another is running breaks the
> latter.
> 
> E.g. playback breaks if capture is stopped when playback is running.
> 
> Move code from startup() and shutdown() to resume() and suspend()
> hooks respectively to fix this issue
> 
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> ---
> v2: - rename from "ASoC: sun4i-i2s: don't try to start up
>                  or shut down DAI if it's active"
>     - move code from startup/shutdown hooks into pm_runtime
> 
>  sound/soc/sunxi/sun4i-i2s.c | 61 +++++++++++++++----------------------
>  1 file changed, 25 insertions(+), 36 deletions(-)
> 
> diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
> index a4aa931ebfae..daa6c08cffbc 100644
> --- a/sound/soc/sunxi/sun4i-i2s.c
> +++ b/sound/soc/sunxi/sun4i-i2s.c
> @@ -644,40 +644,6 @@ static int sun4i_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
>  	return 0;
>  }
>  
> -static int sun4i_i2s_startup(struct snd_pcm_substream *substream,
> -			     struct snd_soc_dai *dai)
> -{
> -	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
> -
> -	/* Enable the whole hardware block */
> -	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> -			   SUN4I_I2S_CTRL_GL_EN, SUN4I_I2S_CTRL_GL_EN);
> -
> -	/* Enable the first output line */
> -	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> -			   SUN4I_I2S_CTRL_SDO_EN_MASK,
> -			   SUN4I_I2S_CTRL_SDO_EN(0));
> -
> -
> -	return clk_prepare_enable(i2s->mod_clk);
> -}
> -
> -static void sun4i_i2s_shutdown(struct snd_pcm_substream *substream,
> -			       struct snd_soc_dai *dai)
> -{
> -	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
> -
> -	clk_disable_unprepare(i2s->mod_clk);
> -
> -	/* Disable our output lines */
> -	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> -			   SUN4I_I2S_CTRL_SDO_EN_MASK, 0);
> -
> -	/* Disable the whole hardware block */
> -	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> -			   SUN4I_I2S_CTRL_GL_EN, 0);
> -}
> -
>  static int sun4i_i2s_set_sysclk(struct snd_soc_dai *dai, int clk_id,
>  				unsigned int freq, int dir)
>  {
> @@ -695,8 +661,6 @@ static const struct snd_soc_dai_ops sun4i_i2s_dai_ops = {
>  	.hw_params	= sun4i_i2s_hw_params,
>  	.set_fmt	= sun4i_i2s_set_fmt,
>  	.set_sysclk	= sun4i_i2s_set_sysclk,
> -	.shutdown	= sun4i_i2s_shutdown,
> -	.startup	= sun4i_i2s_startup,
>  	.trigger	= sun4i_i2s_trigger,
>  };
>  
> @@ -869,6 +833,21 @@ static int sun4i_i2s_runtime_resume(struct device *dev)
>  		goto err_disable_clk;
>  	}
>  
> +	/* Enable the whole hardware block */
> +	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> +			   SUN4I_I2S_CTRL_GL_EN, SUN4I_I2S_CTRL_GL_EN);
> +

So this is definitely needed

> +	/* Enable the first output line */
> +	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
> +			   SUN4I_I2S_CTRL_SDO_EN_MASK,
> +			   SUN4I_I2S_CTRL_SDO_EN(0));
> +
> +	ret = clk_prepare_enable(i2s->mod_clk);
> +	if (ret) {
> +		dev_err(dev, "Failed to enable module clock\n");
> +		goto err_disable_clk;
> +	}

But we really don't want to enable the module clock before the
playback / capture actually starts. And I'm guessing it would make
more sense to keep the output enable configuration there as well,
since it's likely that we will have support for it in the future, and
we'll need additional information from ASoC when we'll do.

Maxime

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com