Say Y here to enable the aggressive power-saving support of
AC97 codecs. In this mode, the power-mode is dynamically
controlled at each open/close.

The mode is activated by passing 'power_save=X' to the
snd-ac97-codec driver module, where 'X' is the time-out
value, a nonnegative integer that specifies how many
seconds of idle time the driver must count before it may
put the AC97 into power-save mode; a value of 0 (zero)
disables the use of this power-save mode.

After the snd-ac97-codec driver module has been loaded,
the 'power_save' parameter can be set via sysfs as follows:

echo 10 > /sys/module/snd_ac97_codec/parameters/power_save

In this case, the time-out is set to 10 seconds; setting
the time-out to 1 second (the minimum activation value)
isn't recommended because many applications try to reopen
the device frequently. A value of 10 seconds would be a
good choice for normal operations.

See Documentation/sound/designs/powersave.rst for more details.