Re: [PATCH] adis16080: fix compiler -Wuninitialized

From: Dan Carpenter
Date: Tue Feb 14 2012 - 10:03:21 EST


On Tue, Feb 14, 2012 at 03:35:36PM +0100, Danny Kukawka wrote:
> Fix for:
> drivers/staging/iio/gyro/adis16080_core.c: In function
> âadis16080_read_rawâ:
> drivers/staging/iio/gyro/adis16080_core.c:99:8: warning: âutâ
> may be used uninitialized in this function [-Wuninitialized]
>
> Initialize ut and change error handling from adis16080_read_raw().
>
> Signed-off-by: Danny Kukawka <danny.kukawka@xxxxxxxxx>
> ---
> drivers/staging/iio/gyro/adis16080_core.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16080_core.c b/drivers/staging/iio/gyro/adis16080_core.c
> index 1815490..e0b2a29 100644
> --- a/drivers/staging/iio/gyro/adis16080_core.c
> +++ b/drivers/staging/iio/gyro/adis16080_core.c
> @@ -82,7 +82,7 @@ static int adis16080_read_raw(struct iio_dev *indio_dev,
> long mask)
> {
> int ret = -EINVAL;
> - u16 ut;
> + u16 ut = 0;
> /* Take the iio_dev status lock */
>
> mutex_lock(&indio_dev->mlock);
> @@ -94,7 +94,7 @@ static int adis16080_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> break;
> ret = adis16080_spi_read(indio_dev, &ut);
> - if (ret < 0)
> + if (ret)
> break;

Either one of these changes would silence the warning from gcc
(which is a false positive). I would keep the "ut = 0;" change and
leave the error handling the same. That way we check for less than
zero consistently instead of checking some for non-zero and some for
less than zero.

I normally wouldn't have commented on this if the changelog had said
whether it was a gcc false positive or if the code changes the
behavior. It really should be mentioned.

If you could put a "Staging:" and an "iio" in the subject, that
would be grand as well. Everyone seems to be using the prefix
"staging:iio:gyro:adis16080" for that file... I don't know why they
don't just use slashes if they're going to specify the whole file...

regards,
dan carpenter

Attachment: signature.asc
Description: Digital signature