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authorTakashi Iwai <tiwai@suse.de>2009-07-23 11:04:13 +0200
committerTakashi Iwai <tiwai@suse.de>2009-07-23 11:09:03 +0200
commitcedb8118e8cef21a2b73fd9cb70660ac19124c16 (patch)
tree080bc68c721b8ed24ebff7c809b7e74f6959148f /Documentation
parent79452f0a28aa5a40522c487b42a5fc423647ad98 (diff)
downloadop-kernel-dev-cedb8118e8cef21a2b73fd9cb70660ac19124c16.zip
op-kernel-dev-cedb8118e8cef21a2b73fd9cb70660ac19124c16.tar.gz
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.txt5
1 files changed, 5 insertions, 0 deletions
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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