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-rw-r--r--Documentation/sound/alsa/ALSA-Configuration.txt20
-rw-r--r--Documentation/sound/alsa/Procfile.txt5
2 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index f9d1114..ad51c93 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -513,6 +513,26 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
or input, but you may use this module for any application which
requires a sound card (like RealPlayer).
+ pcm_devs - Number of PCM devices assigned to each card
+ (default = 1, up to 4)
+ pcm_substreams - Number of PCM substreams assigned to each PCM
+ (default = 8, up to 16)
+ hrtimer - Use hrtimer (=1, default) or system timer (=0)
+ fake_buffer - Fake buffer allocations (default = 1)
+
+ When multiple PCM devices are created, snd-dummy gives different
+ behavior to each PCM device:
+ 0 = interleaved with mmap support
+ 1 = non-interleaved with mmap support
+ 2 = interleaved without mmap
+ 3 = non-interleaved without mmap
+
+ As default, snd-dummy drivers doesn't allocate the real buffers
+ but either ignores read/write or mmap a single dummy page to all
+ buffer pages, in order to save the resouces. If your apps need
+ the read/ written buffer data to be consistent, pass fake_buffer=0
+ option.
+
The power-management is supported.
Module snd-echo3g
diff --git a/Documentation/sound/alsa/Procfile.txt b/Documentation/sound/alsa/Procfile.txt
index 381908d..719a819 100644
--- a/Documentation/sound/alsa/Procfile.txt
+++ b/Documentation/sound/alsa/Procfile.txt
@@ -101,6 +101,8 @@ card*/pcm*/xrun_debug
bit 0 = Enable XRUN/jiffies debug messages
bit 1 = Show stack trace at XRUN / jiffies check
bit 2 = Enable additional jiffies check
+ bit 3 = Log hwptr update at each period interrupt
+ bit 4 = Log hwptr update at each snd_pcm_update_hw_ptr()
When the bit 0 is set, the driver will show the messages to
kernel log when an xrun is detected. The debug message is
@@ -117,6 +119,9 @@ card*/pcm*/xrun_debug
buggy) hardware that doesn't give smooth pointer updates.
This feature is enabled via the bit 2.
+ Bits 3 and 4 are for logging the hwptr records. Note that
+ these will give flood of kernel messages.
+
card*/pcm*/sub*/info
The general information of this PCM sub-stream.
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