linux-kernel - Re: [PATCH] ASoC: rt5682: Properly turn off regulators if wrong device ID

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Date:   Tue, 10 Aug 2021 21:24:21 -0700
From:   Stephen Boyd <swboyd@...omium.org>
To:     Douglas Anderson <dianders@...omium.org>,
        Mark Brown <broonie@...nel.org>,
        Oder Chiou <oder_chiou@...ltek.com>
Cc:     Bard Liao <bardliao@...ltek.com>, Jaroslav Kysela <perex@...ex.cz>,
        Liam Girdwood <lgirdwood@...il.com>,
        Takashi Iwai <tiwai@...e.com>, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ASoC: rt5682: Properly turn off regulators if wrong
 device ID

Quoting Douglas Anderson (2021-08-10 16:59:15)
> When I booted up on a board that had a slightly different codec
> stuffed on it, I got this message at bootup:
>
>   rt5682 9-001a: Device with ID register 6749 is not rt5682
>
> That's normal/expected, but what wasn't normal was the splat that I
> got after:
>
>   WARNING: CPU: 7 PID: 176 at drivers/regulator/core.c:2151 _regulator_put+0x150/0x158
>   pc : _regulator_put+0x150/0x158
>   ...
>   Call trace:
>    _regulator_put+0x150/0x158
>    regulator_bulk_free+0x48/0x70
>    devm_regulator_bulk_release+0x20/0x2c
>    release_nodes+0x1cc/0x244
>    devres_release_all+0x44/0x60
>    really_probe+0x17c/0x378
>    ...
>
> This is because the error paths don't turn off the regulator. Let's
> fix that.
>
> Fixes: 0ddce71c21f0 ("ASoC: rt5682: add rt5682 codec driver")
> Fixes: 87b42abae99d ("ASoC: rt5682: Implement remove callback")
> Signed-off-by: Douglas Anderson <dianders@...omium.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@...omium.org>

>
>  sound/soc/codecs/rt5682-i2c.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/sound/soc/codecs/rt5682-i2c.c b/sound/soc/codecs/rt5682-i2c.c
> index 4a56a52adab5..1cc07812b5ac 100644
> --- a/sound/soc/codecs/rt5682-i2c.c
> +++ b/sound/soc/codecs/rt5682-i2c.c
> @@ -117,6 +117,13 @@ static struct snd_soc_dai_driver rt5682_dai[] = {
>         },
>  };
>
> +static void rt5682_i2c_disable_regulators(void *data)
> +{
> +       struct rt5682_priv *rt5682 = data;
> +
> +       regulator_bulk_disable(ARRAY_SIZE(rt5682->supplies), rt5682->supplies);
> +}
> +
>  static int rt5682_i2c_probe(struct i2c_client *i2c,
>                 const struct i2c_device_id *id)
>  {
> @@ -156,6 +163,10 @@ static int rt5682_i2c_probe(struct i2c_client *i2c,
>                 dev_err(&i2c->dev, "Failed to request supplies: %d\n", ret);
>                 return ret;
>         }

Nit: Add newline here.

> +       ret = devm_add_action_or_reset(&i2c->dev, rt5682_i2c_disable_regulators,
> +                                      rt5682);
> +       if (ret)
> +               return ret;
>
>         ret = regulator_bulk_enable(ARRAY_SIZE(rt5682->supplies),
>                                     rt5682->supplies);
> @@ -285,7 +296,6 @@ static int rt5682_i2c_remove(struct i2c_client *client)
>         struct rt5682_priv *rt5682 = i2c_get_clientdata(client);
>
>         rt5682_i2c_shutdown(client);
> -       regulator_bulk_disable(ARRAY_SIZE(rt5682->supplies), rt5682->supplies);
>
>         return 0;
>  }