On Fri, 7 May 2021 19:30:41 +0100
Colin King <colin.king@xxxxxxxxxxxxx> wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The lux_val returned from tsl2583_get_lux can potentially be zero,
> so check for this to avoid a division by zero and an overflowed
> gain_trim_val.
>
> Fixes clang scan-build warning:
>
> drivers/iio/light/tsl2583.c:345:40: warning: Either the
> condition 'lux_val<0' is redundant or there is division
> by zero at line 345. [zerodivcond]
>
> Fixes: ac4f6eee8fe8 ("staging: iio: TAOS tsl258x: Device driver")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Definitely looks like it could happen so applied to the fixes-togreg branch of
iio.git and marked for stable.
Thanks,
Jonathan
> ---
> drivers/iio/light/tsl2583.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
> index 0f787bfc88fc..c9d8f07a6fcd 100644
> --- a/drivers/iio/light/tsl2583.c
> +++ b/drivers/iio/light/tsl2583.c
> @@ -341,6 +341,14 @@ static int tsl2583_als_calibrate(struct iio_dev *indio_dev)
> return lux_val;
> }
>
> + /* Avoid division by zero of lux_value later on */
> + if (lux_val == 0) {
> + dev_err(&chip->client->dev,
> + "%s: lux_val of 0 will produce out of range trim_value\n",
> + __func__);
> + return -ENODATA;
> + }
> +
> gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target)
> * chip->als_settings.als_gain_trim) / lux_val);
> if ((gain_trim_val < 250) || (gain_trim_val > 4000)) {
