Re: [PATCH 06/13 v2] regulator: max8973: Let core handle GPIO descriptor

From: Charles Keepax
Date: Wed Dec 05 2018 - 08:08:37 EST


On Sat, Dec 01, 2018 at 04:41:44PM +0100, Linus Walleij wrote:
> Use the gpiod_get() rather than the devm_* version so that the
> regulator core can handle the lifecycle of these descriptors.
>
> Fixes: e7d2be696faa ("regulator: max8973: Pass descriptor instead of GPIO number")
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> ChangeLog v1->v2:
> - Drop the gpiod_put() on the errorpath after devm_regulator_register()
> as this will be handled by the regulator core.
> - Fix the second case of devm_gpiod_get()
> - Put a comment in the code so maintainers knows not to
> use managed resources (devm*)
> ---
> @@ -759,9 +759,13 @@ static int max8973_probe(struct i2c_client *client,
> else
> gflags = GPIOD_OUT_LOW;
> gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE;
> - gpiod = devm_gpiod_get_optional(&client->dev,
> - "maxim,enable",
> - gflags);
> + /*
> + * Do not use devm* here: the regulator core takes over the
> + * lifecycle management of the GPIO descriptor.
> + */
> + gpiod = gpiod_get_optional(&client->dev,
> + "maxim,enable",
> + gflags);
> if (IS_ERR(gpiod))
> return PTR_ERR(gpiod);
> if (gpiod) {
> @@ -775,10 +779,13 @@ static int max8973_probe(struct i2c_client *client,
> /*
> * We do not let the core switch this regulator on/off,
> * we just leave it on.
> + *
> + * Do not use devm* here: the regulator core takes over the
> + * lifecycle management of the GPIO descriptor.
> */
> - gpiod = devm_gpiod_get_optional(&client->dev,
> - "maxim,enable",
> - GPIOD_OUT_HIGH);
> + gpiod = gpiod_get_optional(&client->dev,
> + "maxim,enable",
> + GPIOD_OUT_HIGH);

Need to be careful here this path actually never passes the GPIO
to the regulator core. I suspect you want to leave this one as a
devm_

> if (IS_ERR(gpiod))
> return PTR_ERR(gpiod);
> if (gpiod)
> @@ -798,6 +805,8 @@ static int max8973_probe(struct i2c_client *client,
>
> ret = max8973_init_dcdc(max, pdata);
> if (ret < 0) {
> + if (gpiod)
> + gpiod_put(gpiod);

And make this use config.ena_gpiod instead.

Thanks,
Charles