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

[Maxime Ripard]

On Tue, Oct 16, 2018 at 08:08:41PM -0700, Vasily Khoruzhick wrote:
> On Tue, Oct 16, 2018 at 12:16 AM Maxime Ripard
> <maxime.ripard at bootlin.com> wrote:
> >
> > 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.
> 
> Should we go with v1 version of my patch then? I see no reason to
> shuffle code around if we keep startup() and shutdown() hooks.

I'd go for something in between. runtime_pm already provides whether
the device is active or not, so you can just move the
SUN4I_I2S_CTRL_GL_EN write to the runtime_resume and runtime_suspend
functions, and that should fix your issue.

Maxime

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