leds: pca995x: Fix device child node usage in pca995x_probe()

[ Upstream commit 82c5ada1f9d05902a4ccb926c7ce34e2fe699283 ]

The current implementation accesses the `child` fwnode handle outside of
device_for_each_child_node() without incrementing its refcount.

Add the missing call to `fwnode_handle_get(child)`.

The cleanup process where `child` is accessed is not right either
because a single call to `fwnode_handle_put()` is carried out in case of
an error, ignoring unasigned nodes at the point when the error happens.

Keep `child` inside of the first loop, and use the helper pointer that
receives references via `fwnode_handle_get()` to handle the child nodes
within the second loop. Keeping `child` inside the first node has also
the advantage that the scoped version of the loop can be used.

Fixes: ee4e80b2962e ("leds: pca995x: Add support for PCA995X chips")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240807-leds-pca995x-fix-fwnode-usage-v1-1-8057c84dc583@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/leds/leds-pca995x.c b/drivers/leds/leds-pca995x.c
index a5b32eaba7248acc172e27055a2a49f1d8de8a3d..3e56ce90b4b927bd18b44a0ba16a23ad9dba3562 100644 (file)
--- a/drivers/leds/leds-pca995x.c
+++ b/drivers/leds/leds-pca995x.c
@@ -102,11 +102,10 @@ static const struct regmap_config pca995x_regmap = {
 static int pca995x_probe(struct i2c_client *client)
 {
        struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
-       struct fwnode_handle *child;
        struct device *dev = &client->dev;
        struct pca995x_chip *chip;
        struct pca995x_led *led;
-       int i, btype, reg, ret;
+       int i, j, btype, reg, ret;
 
        btype = (unsigned long)device_get_match_data(&client->dev);
 
@@ -124,7 +123,7 @@ static int pca995x_probe(struct i2c_client *client)
 
        i2c_set_clientdata(client, chip);
 
-       device_for_each_child_node(dev, child) {
+       device_for_each_child_node_scoped(dev, child) {
                ret = fwnode_property_read_u32(child, "reg", &reg);
                if (ret)
                        return ret;
@@ -133,7 +132,7 @@ static int pca995x_probe(struct i2c_client *client)
                        return -EINVAL;
 
                led = &chip->leds[reg];
-               led_fwnodes[reg] = child;
+               led_fwnodes[reg] = fwnode_handle_get(child);
                led->chip = chip;
                led->led_no = reg;
                led->ldev.brightness_set_blocking = pca995x_brightness_set;
@@ -152,7 +151,8 @@ static int pca995x_probe(struct i2c_client *client)
                                                     &chip->leds[i].ldev,
                                                     &init_data);
                if (ret < 0) {
-                       fwnode_handle_put(child);
+                       for (j = i; j < PCA995X_MAX_OUTPUTS; j++)
+                               fwnode_handle_put(led_fwnodes[j]);
                        return dev_err_probe(dev, ret,
                                             "Could not register LED %s\n",
                                             chip->leds[i].ldev.name);