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| author | Takashi Iwai <tiwai@suse.de> | 2009-07-23 11:04:13 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-07-23 11:09:03 +0200 |
| commit | cedb8118e8cef21a2b73fd9cb70660ac19124c16 (patch) | |
| tree | 080bc68c721b8ed24ebff7c809b7e74f6959148f /Documentation | |
| parent | 79452f0a28aa5a40522c487b42a5fc423647ad98 (diff) | |
| download | lwn-cedb8118e8cef21a2b73fd9cb70660ac19124c16.tar.gz lwn-cedb8118e8cef21a2b73fd9cb70660ac19124c16.zip | |
ALSA: pcm - Add logging of hwptr updates and interrupt updates
Added the logging functionality to xrun_debug to record the hwptr
updates via snd_pcm_update_hw_ptr() and snd_pcm_update_hwptr_interrupt(),
corresponding to 16 and 8, respectively.
For example,
# echo 9 > /proc/asound/card0/pcm0p/xrun_debug
will record the position and other parameters at each period interrupt
together with the normal XRUN debugging.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/sound/alsa/Procfile.txt | 5 |
1 files changed, 5 insertions, 0 deletions
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. |