path: root/sound/drivers
diff options
authorTakashi Iwai <>2010-08-05 11:17:04 +0200
committerTakashi Iwai <>2010-08-05 11:17:04 +0200
commit74bf40f0793fed9e01eb6164c2ce63e8c27ca205 (patch)
treef41312c0943978842ac258873b29da04d72d0625 /sound/drivers
parente71981343ad29b5d929f82ac56c0b27b8ea0e540 (diff)
parentc4685849b4d725ab80cd29f5e09f5f128b4724b5 (diff)
Merge branch 'topic/misc' into for-linus
Diffstat (limited to 'sound/drivers')
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.
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.