From 1d8c1100fbf956b9c5994077a4d3c6490c23e087 Mon Sep 17 00:00:00 2001 From: Michael Witten Date: Wed, 14 Jul 2010 23:54:21 +0000 Subject: 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 Signed-off-by: Takashi Iwai --- sound/drivers/Kconfig | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig index 84714a65e5c..32646000ab9 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 -- cgit v1.2.3-18-g5258