linux-kernel - [PATCH] leds: powernv: replace of_node_put to _

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Message-Id: <20240529195354.1187882-1-marilene.agarcia@gmail.com>
Date: Wed, 29 May 2024 16:53:54 -0300
From: MarileneGarcia <marilene.agarcia@...il.com>
To: Pavel Machek <pavel@....cz>,
	Lee Jones <lee@...nel.org>,
	Michael Ellerman <mpe@...erman.id.au>,
	Nicholas Piggin <npiggin@...il.com>,
	Christophe Leroy <christophe.leroy@...roup.eu>,
	"Naveen N. Rao" <naveen.n.rao@...ux.ibm.com>,
	Julia Lawall <julia.lawall@...ia.fr>
Cc: MarileneGarcia <marilene.agarcia@...il.com>,
	Shuah Khan <skhan@...uxfoundation.org>,
	Javier Carrasco <javier.carrasco.cruz@...il.com>,
	linux-leds@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] leds: powernv: replace of_node_put to __free

Use __free for device_node values, and thus drop calls to
of_node_put.

The variable attribute __free adds a scope based cleanup to
the device node. The goal is to reduce memory management issues
in the kernel code.

The of_node_put calls were removed, and the
for_each_available_child_of_node was replaced to the equivalent
for_each_available_child_of_node_scoped which use the __free.

Suggested-by: Julia Lawall <julia.lawall@...ia.fr>
Signed-off-by: MarileneGarcia <marilene.agarcia@...il.com>
---
Changes:
These changes intend to add the new __free cleanup handler 
to device_node initialisations, which ensures that the resource is 
freed as soon as the variable goes out of scope. Thus removing the 
need to manually free up the resource using of_node_put

Thank you.

 drivers/leds/leds-powernv.c | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/drivers/leds/leds-powernv.c b/drivers/leds/leds-powernv.c
index 4f01acb75727..68fe47cd1a4f 100644
--- a/drivers/leds/leds-powernv.c
+++ b/drivers/leds/leds-powernv.c
@@ -246,29 +246,25 @@ static int powernv_led_classdev(struct platform_device *pdev,
 	const char *cur = NULL;
 	int rc = -1;
 	struct property *p;
-	struct device_node *np;
 	struct powernv_led_data *powernv_led;
 	struct device *dev = &pdev->dev;
 
-	for_each_available_child_of_node(led_node, np) {
+	for_each_available_child_of_node_scoped(led_node, np) {
 		p = of_find_property(np, "led-types", NULL);
 
 		while ((cur = of_prop_next_string(p, cur)) != NULL) {
 			powernv_led = devm_kzalloc(dev, sizeof(*powernv_led),
 						   GFP_KERNEL);
-			if (!powernv_led) {
-				of_node_put(np);
+			if (!powernv_led)
 				return -ENOMEM;
-			}
 
 			powernv_led->common = powernv_led_common;
 			powernv_led->loc_code = (char *)np->name;
 
 			rc = powernv_led_create(dev, powernv_led, cur);
-			if (rc) {
-				of_node_put(np);
+			if (rc)
 				return rc;
-			}
+
 		} /* while end */
 	}
 
@@ -278,12 +274,10 @@ static int powernv_led_classdev(struct platform_device *pdev,
 /* Platform driver probe */
 static int powernv_led_probe(struct platform_device *pdev)
 {
-	struct device_node *led_node;
 	struct powernv_led_common *powernv_led_common;
 	struct device *dev = &pdev->dev;
-	int rc;
-
-	led_node = of_find_node_by_path("/ibm,opal/leds");
+	struct device_node *led_node __free(device_node) =
+							of_find_node_by_path("/ibm,opal/leds");
 	if (!led_node) {
 		dev_err(dev, "%s: LED parent device node not found\n",
 			__func__);
@@ -292,20 +286,15 @@ static int powernv_led_probe(struct platform_device *pdev)
 
 	powernv_led_common = devm_kzalloc(dev, sizeof(*powernv_led_common),
 					  GFP_KERNEL);
-	if (!powernv_led_common) {
-		rc = -ENOMEM;
-		goto out;
-	}
+	if (!powernv_led_common)
+		return -ENOMEM;
 
 	mutex_init(&powernv_led_common->lock);
 	powernv_led_common->max_led_type = cpu_to_be64(OPAL_SLOT_LED_TYPE_MAX);
 
 	platform_set_drvdata(pdev, powernv_led_common);
 
-	rc = powernv_led_classdev(pdev, led_node, powernv_led_common);
-out:
-	of_node_put(led_node);
-	return rc;
+	return powernv_led_classdev(pdev, led_node, powernv_led_common);
 }
 
 /* Platform driver remove */
-- 
2.34.1