Re: [PATCH 01/50] pinctrl: Add devm_ apis for pinctrl_{register, unregister}

Bjorn Andersson
2016-02-24T18:21:22Z

On Wed 24 Feb 05:15 PST 2016, Laxman Dewangan wrote:

> Add device managed APIs devm_pinctrl_register() and
> devm_pinctrl_unregister() for the APIs pinctrl_register()
> and pinctrl_unregister().
>
> This helps in reducing code in error path and sometimes
> removal of .remove callback for driver unbind.
>
> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
> ---
> drivers/pinctrl/core.c | 69 +++++++++++++++++++++++++++++++++++++++++
> include/linux/pinctrl/pinctrl.h | 6 ++++
> 2 files changed, 75 insertions(+)
>
> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
[..]
> +static int devm_pinctrl_dev_match(struct device *dev, void *res, void *data)
> +{
> + struct pctldev **r = res;
> +
> + if (!r || !*r) {
> + WARN_ON(!r || !*r);
> + return 0;
> + }

The idiomatic way is to wrap your condition in the WARN_ON; i.e.

if (WARN_ON(!r || !*r))
return 0;

> +
> + return *r == data;
> +}
> +
[..]
> +
> +/**
> + * devm_pinctrl_unregister() - Resource manager of pinctrl_unregister()
> + * @dev: device for which which resource was allocated
> + * @pctldev: the pinctrl device to unregister.
> + */
> +void devm_pinctrl_unregister(struct device *dev, struct pinctrl_dev *pctldev)
> +{
> + int ret;
> +
> + ret = devres_release(dev, devm_pinctrl_dev_release,
> + devm_pinctrl_dev_match, pctldev);
> + if (!ret)
> + WARN_ON(ret);

ret is unlikely to be non-zero in a code path only taken when ret is
zero.

Do either:

WARN_ON(devres_release(...));

rc = devres_release(..);
WARN_ON(rc);

> +}
> +EXPORT_SYMBOL_GPL(devm_pinctrl_unregister);
> +
> static int __init pinctrl_init(void)
> {
> pr_info("initialized pinctrl subsystem\n");
> diff --git a/include/linux/pinctrl/pinctrl.h b/include/linux/pinctrl/pinctrl.h
> index 9ba59fc..a42e57d 100644
> --- a/include/linux/pinctrl/pinctrl.h
> +++ b/include/linux/pinctrl/pinctrl.h
> @@ -144,6 +144,12 @@ struct pinctrl_desc {
> extern struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
> struct device *dev, void *driver_data);
> extern void pinctrl_unregister(struct pinctrl_dev *pctldev);
> +extern struct pinctrl_dev *devm_pinctrl_register(struct device *dev,
> + struct pinctrl_desc *pctldesc,
> + void *driver_data);
> +extern void devm_pinctrl_unregister(struct device *dev,
> + struct pinctrl_dev *pctldev);
> +
> extern bool pin_is_valid(struct pinctrl_dev *pctldev, int pin);
> extern void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
> struct pinctrl_gpio_range *range);

Apart from these style issues you have my ack.

Regards,
Bjorn