[alsa-devel] [PATCH] Fix logical-not-parentheses warning

[Joe Perches]

On Sun, 2015-08-02 at 02:08 -0700, Tomer Barletz wrote:
> This fixes the following warning, that is seen with gcc 5.1:
> warning: logical not is only applied to the left hand side of 
> comparison [-Wlogical-not-parentheses].
[]
> diff --git a/sound/pci/oxygen/oxygen_mixer.c 
[]
> 
@@ -88,7 +88,7 @@ static int dac_mute_put(struct snd_kcontrol *ctl,
>       int changed;
>  
>       mutex_lock(&chip->mutex);
> -     changed = !value->value.integer.value[0] != chip->dac_mute;
> +     changed = (!value->value.integer.value[0]) != chip->dac_mute;

It seems this is because dac_mute's value is inverted
0 means true, 1 is false.

I think it'd be simpler if dac_mute was converted to a
standard bool (or perhaps renamed to not_muted) and
this test was rewritten.

Using !!value->value.integer.value[0] would also be
more readable and intelligible.