[PATCH v5] powerpc:85xx: Add missing of_node_put() in sgy_cst1000

From: Liang He
Date: Fri Jun 17 2022 - 06:54:00 EST


In gpio_halt_probe(), of_find_matching_node() will return a node
pointer with refcount incremented. We should use of_node_put() in
fail path or when it is not used anymore.

Signed-off-by: Liang He <windhl@xxxxxxx>
---
changelog:
v5: fix 'gotot' error introduced by v4 and use cross-compiler to test
v4: reuse exist 'err' and use a simple code style, advised by CJ
v3: use local 'child_node' advised by Michael.
v2: use goto-label patch style advised by Christophe Leroy.
v1: add of_node_put() before each exit.

arch/powerpc/platforms/85xx/sgy_cts1000.c | 35 ++++++++++++++---------
1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/platforms/85xx/sgy_cts1000.c b/arch/powerpc/platforms/85xx/sgy_cts1000.c
index 98ae64075193..e14d1b74d4e4 100644
--- a/arch/powerpc/platforms/85xx/sgy_cts1000.c
+++ b/arch/powerpc/platforms/85xx/sgy_cts1000.c
@@ -71,6 +71,7 @@ static int gpio_halt_probe(struct platform_device *pdev)
{
enum of_gpio_flags flags;
struct device_node *node = pdev->dev.of_node;
+ struct device_node *child_node;
int gpio, err, irq;
int trigger;

@@ -78,26 +79,29 @@ static int gpio_halt_probe(struct platform_device *pdev)
return -ENODEV;

/* If there's no matching child, this isn't really an error */
- halt_node = of_find_matching_node(node, child_match);
- if (!halt_node)
+ child_node = of_find_matching_node(node, child_match);
+ if (!child_node)
return 0;

/* Technically we could just read the first one, but punish
* DT writers for invalid form. */
- if (of_gpio_count(halt_node) != 1)
- return -EINVAL;
+ if (of_gpio_count(child_node) != 1) {
+ err = -EINVAL;
+ goto err_put;
+ }

/* Get the gpio number relative to the dynamic base. */
- gpio = of_get_gpio_flags(halt_node, 0, &flags);
- if (!gpio_is_valid(gpio))
- return -EINVAL;
+ gpio = of_get_gpio_flags(child_node, 0, &flags);
+ if (!gpio_is_valid(gpio)) {
+ err = -EINVAL;
+ goto err_put;
+ }

err = gpio_request(gpio, "gpio-halt");
if (err) {
printk(KERN_ERR "gpio-halt: error requesting GPIO %d.\n",
gpio);
- halt_node = NULL;
- return err;
+ goto err_put;
}

trigger = (flags == OF_GPIO_ACTIVE_LOW);
@@ -105,15 +109,14 @@ static int gpio_halt_probe(struct platform_device *pdev)
gpio_direction_output(gpio, !trigger);

/* Now get the IRQ which tells us when the power button is hit */
- irq = irq_of_parse_and_map(halt_node, 0);
+ irq = irq_of_parse_and_map(child_node, 0);
err = request_irq(irq, gpio_halt_irq, IRQF_TRIGGER_RISING |
- IRQF_TRIGGER_FALLING, "gpio-halt", halt_node);
+ IRQF_TRIGGER_FALLING, "gpio-halt", child_node);
if (err) {
printk(KERN_ERR "gpio-halt: error requesting IRQ %d for "
"GPIO %d.\n", irq, gpio);
gpio_free(gpio);
- halt_node = NULL;
- return err;
+ goto err_put;
}

/* Register our halt function */
@@ -123,7 +126,12 @@ static int gpio_halt_probe(struct platform_device *pdev)
printk(KERN_INFO "gpio-halt: registered GPIO %d (%d trigger, %d"
" irq).\n", gpio, trigger, irq);

+ halt_node = child_node;
return 0;
+
+err_put:
+ of_node_put(child_node);
+ return err;
}

static int gpio_halt_remove(struct platform_device *pdev)
@@ -139,6 +147,7 @@ static int gpio_halt_remove(struct platform_device *pdev)

gpio_free(gpio);

+ of_node_put(halt_node);
halt_node = NULL;
}

--
2.25.1