- This file appears when CONFIG_SND_DEBUG=y.
- This shows the status of xrun (= buffer overrun/xrun) debug of
- ALSA PCM middle layer, as an integer from 0 to 2. The value
- can be changed by writing to this file, such as
-
- # cat 2 > /proc/asound/card0/pcm0p/xrun_debug
-
- When this value is greater than 0, the driver will show the
- messages to kernel log when an xrun is detected. The debug
- message is shown also when the invalid H/W pointer is detected
- at the update of periods (usually called from the interrupt
+ This file appears when CONFIG_SND_DEBUG=y and
+ CONFIG_PCM_XRUN_DEBUG=y.
+ This shows the status of xrun (= buffer overrun/xrun) and
+ invalid PCM position debug/check of ALSA PCM middle layer.
+ It takes an integer value, can be changed by writing to this
+ file, such as
+
+ # cat 5 > /proc/asound/card0/pcm0p/xrun_debug
+
+ The value consists of the following bit flags:
+ bit 0 = Enable XRUN/jiffies debug messages
+ bit 1 = Show stack trace at XRUN / jiffies check
+ bit 2 = Enable additional jiffies check
+
+ When the bit 0 is set, the driver will show the messages to
+ kernel log when an xrun is detected. The debug message is
+ shown also when the invalid H/W pointer is detected at the
+ update of periods (usually called from the interrupt