[PATCH] leds-pca955x: Add proper error handling and fix bogus memory handling

[Sven Wegener]

Check the return value of led_classdev_register and unregister all registered
devices, if registering one device fails. Also the dynamic memory handling is
totally bogus. You can't allocate multiple chunks via kzalloc() and expect them
to be in order later.

Signed-off-by: Sven Wegener <sven.wegener@xxxxxxxxxxx>
Acked-by: Nate Case <ncase@xxxxxxxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
---
 drivers/leds/leds-pca955x.c |   70 +++++++++++++++++++++++-------------------
 1 files changed, 38 insertions(+), 32 deletions(-)

diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index 146c069..f508729 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -248,11 +248,10 @@ static int __devinit pca955x_probe(struct i2c_client *client,
 					const struct i2c_device_id *id)
 {
 	struct pca955x_led *pca955x;
-	int i;
-	int err = -ENODEV;
 	struct pca955x_chipdef *chip;
 	struct i2c_adapter *adapter;
 	struct led_platform_data *pdata;
+	int i, err;
 
 	chip = &pca955x_chipdefs[id->driver_data];
 	adapter = to_i2c_adapter(client->dev.parent);
@@ -282,43 +281,41 @@ static int __devinit pca955x_probe(struct i2c_client *client,
 		}
 	}
 
+	pca955x = kzalloc(sizeof(*pca955x) * chip->bits, GFP_KERNEL);
+	if (!pca955x)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, pca955x);
+
 	for (i = 0; i < chip->bits; i++) {
-		pca955x = kzalloc(sizeof(struct pca955x_led), GFP_KERNEL);
-		if (!pca955x) {
-			err = -ENOMEM;
-			goto exit;
-		}
+		pca955x[i].chipdef = chip;
+		pca955x[i].client = client;
+		pca955x[i].led_num = i;
 
-		pca955x->chipdef = chip;
-		pca955x->client = client;
-		pca955x->led_num = i;
 		/* Platform data can specify LED names and default triggers */
 		if (pdata) {
 			if (pdata->leds[i].name)
-				snprintf(pca955x->name, 32, "pca955x:%s",
-							pdata->leds[i].name);
+				snprintf(pca955x[i].name,
+					 sizeof(pca955x[i].name), "pca955x:%s",
+					 pdata->leds[i].name);
 			if (pdata->leds[i].default_trigger)
-				pca955x->led_cdev.default_trigger =
+				pca955x[i].led_cdev.default_trigger =
 					pdata->leds[i].default_trigger;
 		} else {
-			snprintf(pca955x->name, 32, "pca955x:%d", i);
+			snprintf(pca955x[i].name, sizeof(pca955x[i].name),
+				 "pca955x:%d", i);
 		}
-		spin_lock_init(&pca955x->lock);
 
-		pca955x->led_cdev.name = pca955x->name;
-		pca955x->led_cdev.brightness_set =
-				pca955x_led_set;
+		spin_lock_init(&pca955x[i].lock);
 
-		/*
-		 * Client data is a pointer to the _first_ pca955x_led
-		 * struct
-		 */
-		if (i == 0)
-			i2c_set_clientdata(client, pca955x);
+		pca955x[i].led_cdev.name = pca955x[i].name;
+		pca955x[i].led_cdev.brightness_set = pca955x_led_set;
 
-		INIT_WORK(&(pca955x->work), pca955x_led_work);
+		INIT_WORK(&pca955x[i].work, pca955x_led_work);
 
-		led_classdev_register(&client->dev, &(pca955x->led_cdev));
+		err = led_classdev_register(&client->dev, &pca955x[i].led_cdev);
+		if (err < 0)
+			goto exit;
 	}
 
 	/* Turn off LEDs */
@@ -336,23 +333,32 @@ static int __devinit pca955x_probe(struct i2c_client *client,
 	pca955x_write_psc(client, 1, 0);
 
 	return 0;
+
 exit:
+	while (i--) {
+		led_classdev_unregister(&pca955x[i].led_cdev);
+		cancel_work_sync(&pca955x[i].work);
+	}
+
+	kfree(pca955x);
+	i2c_set_clientdata(client, NULL);
+
 	return err;
 }
 
 static int __devexit pca955x_remove(struct i2c_client *client)
 {
 	struct pca955x_led *pca955x = i2c_get_clientdata(client);
-	int leds = pca955x->chipdef->bits;
 	int i;
 
-	for (i = 0; i < leds; i++) {
-		led_classdev_unregister(&(pca955x->led_cdev));
-		cancel_work_sync(&(pca955x->work));
-		kfree(pca955x);
-		pca955x = pca955x + 1;
+	for (i = 0; i < pca955x->chipdef->bits; i++) {
+		led_classdev_unregister(&pca955x[i].led_cdev);
+		cancel_work_sync(&pca955x[i].work);
 	}
 
+	kfree(pca955x);
+	i2c_set_clientdata(client, NULL);
+
 	return 0;
 }
 
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