Update the value on the given register
int snd_ac97_update(struct snd_ac97 * ac97, unsigned short reg, unsigned short value);
ac97
the ac97 instance
reg
the register to change
value
the value to set
Compares the value with the register cache and updates the value only when the value is changed.
1 if the value is changed, 0 if no change, or a negative code on failure.