Merge branch 'topic/aloop' into topic/misc

[linux-2.6.git] / sound / drivers / Kconfig

diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig
index 84714a65e5c81a0a777577cc78ce115f4f3a99c2..c8961165277cce21a85147d6571cf014e86bf13d 100644 (file)
--- a/sound/drivers/Kconfig
+++ b/sound/drivers/Kconfig
@@ -74,6 +74,25 @@ config SND_DUMMY
          To compile this driver as a module, choose M here: the module
          will be called snd-dummy.
 
+config SND_ALOOP
+        tristate "Generic loopback driver (PCM)"
+        select SND_PCM
+        help
+          Say 'Y' or 'M' to include support for the PCM loopback device.
+         This module returns played samples back to the user space using
+         the standard ALSA PCM device. The devices are routed 0->1 and
+          1->0, where first number is the playback PCM device and second
+         number is the capture device. Module creates two PCM devices and
+         configured number of substreams (see the pcm_substreams module
+          parameter).
+
+         The looback device allow time sychronization with an external
+         timing source using the time shift universal control (+-20%
+         of system time).
+
+         To compile this driver as a module, choose M here: the module
+         will be called snd-aloop.
+
 config SND_VIRMIDI
        tristate "Virtual MIDI soundcard"
        depends on SND_SEQUENCER
@@ -155,7 +174,7 @@ config SND_ML403_AC97CR
        select SND_AC97_CODEC
        help
          Say Y here to include support for the
-         opb_ac97_controller_ref_v1_00_a ip core found in Xilinx' ML403
+         opb_ac97_controller_ref_v1_00_a ip core found in Xilinx's ML403
          reference design.
 
          To compile this driver as a module, choose M here: the module
@@ -170,9 +189,25 @@ 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 +217,6 @@ 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