Currently, if the DT does not define num-interpolated-steps then num_steps is undefined and the interpolation code will deploy randomly. Fix this.
Fixes: 573fe6d1c25c ("backlight: pwm_bl: Linear interpolation between brightness-levels") Reported-by: Marcel Ziswiler marcel.ziswiler@toradex.com Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Marcel Ziswiler marcel.ziswiler@toradex.com Tested-by: Marcel Ziswiler marcel.ziswiler@toradex.com --- drivers/video/backlight/pwm_bl.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 9ee4c1b735b2..e3c22b79fbcd 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -299,15 +299,14 @@ static int pwm_backlight_parse_dt(struct device *dev, * interpolation between each of the values of brightness levels * and creates a new pre-computed table. */ - of_property_read_u32(node, "num-interpolated-steps", - &num_steps); - - /* - * Make sure that there is at least two entries in the - * brightness-levels table, otherwise we can't interpolate - * between two points. - */ - if (num_steps) { + if ((of_property_read_u32(node, "num-interpolated-steps", + &num_steps) == 0) && num_steps) { + /* + * Make sure that there is at least two entries in the + * brightness-levels table, otherwise we can't + * interpolate + * between two points. + */ if (data->max_brightness < 2) { dev_err(dev, "can't interpolate\n"); return -EINVAL; -- 2.17.1