Re: [PATCH 2/3] regulator: Only free GPIOs if the core requested them

From: Marek Szyprowski
Date: Fri Nov 23 2018 - 04:24:52 EST


Hi Charles,

On 2018-11-22 18:30, Charles Keepax wrote:
> Currently, the regulator core will take ownership of any GPIO passed
> into it. Makes end driver code fairly error prone as the normal devm_
> patterns of allocation don't work. Update the regulator core to only
> free the GPIO if it requested it, this allows the drivers to manage the
> GPIO lifetime as they normally would.
>
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>

Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

> ---
> drivers/regulator/core.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
> index dbe2f2e6e6254..9da7d27c7145e 100644
> --- a/drivers/regulator/core.c
> +++ b/drivers/regulator/core.c
> @@ -83,6 +83,7 @@ struct regulator_enable_gpio {
> u32 enable_count; /* a number of enabled shared GPIO */
> u32 request_count; /* a number of requested shared GPIO */
> unsigned int ena_gpio_invert:1;
> + unsigned int locally_requested:1;
> };
>
> /*
> @@ -2233,19 +2234,20 @@ static int regulator_ena_gpio_request(struct regulator_dev *rdev,
> }
> }
>
> + pin = kzalloc(sizeof(struct regulator_enable_gpio), GFP_KERNEL);
> + if (pin == NULL)
> + return -ENOMEM;
> +
> if (!config->ena_gpiod) {
> ret = gpio_request_one(config->ena_gpio,
> GPIOF_DIR_OUT | config->ena_gpio_flags,
> rdev_get_name(rdev));
> - if (ret)
> + if (ret) {
> + kfree(pin);
> return ret;
> - }
> + }
>
> - pin = kzalloc(sizeof(struct regulator_enable_gpio), GFP_KERNEL);
> - if (pin == NULL) {
> - if (!config->ena_gpiod)
> - gpio_free(config->ena_gpio);
> - return -ENOMEM;
> + pin->locally_requested = 1;
> }
>
> pin->gpiod = gpiod;
> @@ -2270,7 +2272,8 @@ static void regulator_ena_gpio_free(struct regulator_dev *rdev)
> if (pin->gpiod == rdev->ena_pin->gpiod) {
> if (pin->request_count <= 1) {
> pin->request_count = 0;
> - gpiod_put(pin->gpiod);
> + if (pin->locally_requested)
> + gpiod_put(pin->gpiod);
> list_del(&pin->list);
> kfree(pin);
> rdev->ena_pin = NULL;

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland