diff options
Diffstat (limited to 'Documentation/sound')
| -rw-r--r-- | Documentation/sound/alsa/ALSA-Configuration.txt | 20 | ||||
| -rw-r--r-- | Documentation/sound/alsa/Procfile.txt | 5 |
2 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt index f9d11140af91..ad51c93d41e4 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 381908d8ca42..719a819f8cc2 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. |