diff options
| -rw-r--r-- | sound/drivers/Kconfig | 24 |
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 |