ALSA: Kconfig: SND_AC97_POWER_SAVE description improvement

The description has been expanded to explain the time-out
value provided by the power_save module parameter.

Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 21 insertions, 3 deletions

diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig
index 84714a65e5c8..32646000ab90 100644
--- a/sound/drivers/Kconfig
+++ b/sound/drivers/Kconfig
@@ -170,9 +170,25 @@ config SND_AC97_POWER_SAVE
           AC97 codecs.  In this mode, the power-mode is dynamically
           controlled at each open/close.
 
-          The mode is activated by passing power_save=1 option to
-          snd-ac97-codec driver.  You can toggle it dynamically over
-          sysfs, too.
+          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/alsa/powersave.txt for more details.
 
 config SND_AC97_POWER_SAVE_DEFAULT
         int "Default time-out for AC97 power-save mode"
@@ -182,4 +198,6 @@ config SND_AC97_POWER_SAVE_DEFAULT
           The default time-out value in seconds for AC97 automatic
           power-save mode.  0 means to disable the power-save mode.
 
+          See SND_AC97_POWER_SAVE for more details.
+
 endif   # SND_DRIVERS