staging: iio: light: Fix compiler warning in tsl2563.c

PATCH In review Maxin B. John 3 participants 3 messages Sep 1, 2011 – Sep 2, 2011

Subsystems (3)

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Maxin B. John

author

2011-09-01 21:24 UTC #0 lore raw

PATCH 1/1 staging: iio: light: Fix compiler warning in tsl2563.c

CC [M] drivers/staging/iio/light/tsl2563.o
drivers/staging/iio/light/tsl2563.c: In function 'tsl2563_probe':
drivers/staging/iio/light/tsl2563.c:736: warning: 'id' may be used uninitialized in this function

Also fixes the tsl2563_read_id().

Signed-off-by Maxin B. John <[email protected]>

---

drivers/staging/iio/light/tsl2563.c +8 -6

index f25243b..f8f787d 100644
@@ -225,9 +225,9 @@ static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id)
 
 	ret = i2c_smbus_read_byte_data(client, TSL2563_CMD | TSL2563_REG_ID);
 	if (ret < 0)
-		return ret;
+		return -EIO;
 
-	return 0;
+	return ret;
 }
 
 /*

@@ -697,7 +697,7 @@ static int __devinit tsl2563_probe(struct i2c_client *client,
 	struct tsl2563_platform_data *pdata = client->dev.platform_data;
 	int err = 0;
 	int ret;
-	u8 id;
+	u8 id = 0;
 
 	indio_dev = iio_allocate_device(sizeof(*chip));
 	if (!indio_dev)

@@ -709,15 +709,17 @@ static int __devinit tsl2563_probe(struct i2c_client *client,
 	chip->client = client;
 
 	err = tsl2563_detect(chip);
-	if (err) {
+	if (err < 0) {
 		dev_err(&client->dev, "device not found, error %d\n", -err);
 		goto fail1;
 	}
 
 	err = tsl2563_read_id(chip, &id);
-	if (err)
+	if (err < 0) {
+		dev_err(&client->dev, "id reading failed, error %d\n", -err);
 		goto fail1;
-
+	}
+	id = err;
 	mutex_init(&chip->lock);
 
 	/* Default values used until userspace says otherwise */

Dan Carpenter

2011-09-01 21:55 UTC #1 lore raw

drivers/staging/iio/light/tsl2563.c static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id) · line 228

Quoted 8 lines · Maxin B. John

drivers/staging/iio/light/tsl2563.c +1 -1

@@ -225,9 +225,9 @@ static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id)
 
 	ret = i2c_smbus_read_byte_data(client, TSL2563_CMD | TSL2563_REG_ID);
 	if (ret < 0)
-		return ret;
+		return -EIO;

Don't overwrite the error code. For example, the lower layers can return -EAGAIN and that's more useful than just returning -EIO every time.

Your fix works, but it's not very clean. Just add a "*id = ret;" line before the "return 0;" and that's it. (It doesn't make sense to pass a pointer to "id" and not use it).

(In other words, don't make any changes to the tsl2563_probe() function)

drivers/staging/iio/light/tsl2563.c static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id) · line 232

Quoted 5 lines

drivers/staging/iio/light/tsl2563.c +1 -1
-	return 0;
+	return ret;
 }
 

regards,
dan carpenter

Jonathan Cameron

2011-09-02 09:03 UTC #2 lore raw

Quoted 18 lines · Dan Carpenter

drivers/staging/iio/light/tsl2563.c static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id) · line 228
Quoted 8 lines · Maxin B. John
drivers/staging/iio/light/tsl2563.c +1 -1
@@ -225,9 +225,9 @@ static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id)
 
 	ret = i2c_smbus_read_byte_data(client, TSL2563_CMD | TSL2563_REG_ID);
 	if (ret < 0)
-		return ret;
+		return -EIO;
Don't overwrite the error code. For example, the lower layers can return -EAGAIN and that's more useful than just returning -EIO every time.
Your fix works, but it's not very clean. Just add a "*id = ret;" line before the "return 0;" and that's it. (It doesn't make sense to pass a pointer to "id" and not use it).

Quoted 8 lines

(In other words, don't make any changes to the tsl2563_probe() function)
drivers/staging/iio/light/tsl2563.c static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id) · line 232
Quoted 5 lines
drivers/staging/iio/light/tsl2563.c +1 -1
-	return 0;
+	return ret;
 }
 

Yikes - I wonder why my various compilers don't throw that up. Ah well Dan's fix is indeed the right one and what was intended.

Thanks,

Jonathan