Re: [PATCH 01/21] pinctrl: ti: iodelay: Use scope based of_node_put() cleanups

From: Dan Carpenter
Date: Wed May 01 2024 - 09:33:00 EST


On Wed, May 01, 2024 at 08:55:59PM +0800, Peng Fan (OSS) wrote:
> @@ -879,16 +874,12 @@ static int ti_iodelay_probe(struct platform_device *pdev)
> ret = pinctrl_register_and_init(&iod->desc, dev, iod, &iod->pctl);
> if (ret) {
> dev_err(dev, "Failed to register pinctrl\n");
> - goto exit_out;
> + return ret;
> }
>
> platform_set_drvdata(pdev, iod);
>
> return pinctrl_enable(iod->pctl);
> -
> -exit_out:
> - of_node_put(np);
> - return ret;
> }

This will call of_node_put() on the success path so it's a behavior
change. The original code is buggy, it's supposed to call of_node_put()
on the success path here or in ti_iodelay_remove().

If it's supposed to call of_node_put() here, then fine, this is bugfix
but if it's supposed to call it in ti_iodelay_remove() then we need to
save the pointer somewhere using no_free_ptr(). Probably saving ->np
is the safest choice?

The original code is already a little bit buggy because it doesn't
check for pinctrl_enable() errors and cleanup.


diff --git a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
index 040f2c46a868..f40a1476e4ff 100644
--- a/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
+++ b/drivers/pinctrl/ti/pinctrl-ti-iodelay.c
@@ -156,6 +156,7 @@ struct ti_iodelay_device {

const struct ti_iodelay_reg_data *reg_data;
struct ti_iodelay_reg_values reg_init_conf_values;
+ struct device_node *np;
};

/**
@@ -884,7 +885,12 @@ static int ti_iodelay_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, iod);

- return pinctrl_enable(iod->pctl);
+ ret = pinctrl_enable(iod->pctl);
+ if (ret)
+ goto exit_out;
+
+ iod->np = no_free_ptr(np);
+ return 0;

exit_out:
of_node_put(np);
@@ -903,6 +909,7 @@ static void ti_iodelay_remove(struct platform_device *pdev)
pinctrl_unregister(iod->pctl);

ti_iodelay_pinconf_deinit_dev(iod);
+ of_node_put(iod->np);

/* Expect other allocations to be freed by devm */
}