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

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].

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diff --git a/sound/pci/oxygen/oxygen_mixer.c

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@@ -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.