kernel/git/stable/linux.git/Documentation/sound/alsa/Procfile.txt, branch master

ALSA: doc: ReSTize Procfile document

2016-11-10T17:09:21+00:00

A simple conversion from a text file. A new subidrectory, Documentation/sound/designs, was created to put this document. The other API design and implementation docuemnts will be put to that directory in later commits. Signed-off-by: Takashi Iwai

ALSA: pcm: Add xrun_injection proc entry

2014-11-04T13:09:16+00:00

This patch adds a new proc entry for PCM substreams to inject an XRUN. When a PCM substream is running and any value is written to its xrun_injection proc file, the driver triggers XRUN. This is a useful feature for debugging XRUN and error handling code paths. Note that this entry is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai

ALSA: pcm: Replace PCM hwptr tracking with tracepoints

2014-11-04T13:09:14+00:00

ALSA PCM core has a mechanism tracking the PCM hwptr updates for analyzing XRUNs. But its log is limited (up to 10) and its log output is a kernel message, which is hard to handle. In this patch, the hwptr logging is moved to the tracing infrastructure instead of its own. Not only the hwptr updates but also XRUN and hwptr errors are recorded on the trace log, so that user can see such events at the exact timing. The new "snd_pcm" entry will appear in the tracing events: # ls -F /sys/kernel/debug/tracing/events/snd_pcm enable filter hw_ptr_error/ hwptr/ xrun/ The hwptr is for the regular hwptr update events. An event trace looks like: aplay-26187 [004] d..3 4012.834761: hwptr: pcmC0D0p/sub0: POS: pos=488, old=0, base=0, period=1024, buf=16384 "POS" shows the hwptr update by the explicit position update call and "IRQ" means the hwptr update by the interrupt, i.e. snd_pcm_period_elapsed() call. The "pos" is the passed ring-buffer offset by the caller, "old" is the previous hwptr, "base" is the hwptr base position, "period" and "buf" are period- and buffer-size of the target PCM substream. (Note that the hwptr position displayed here isn't the ring-buffer offset. It increments up to the PCM position boundary.) The XRUN event appears similarly, but without "pos" field. The hwptr error events appear with the PCM identifier and its reason string, such as "Lost interrupt?". The XRUN and hwptr error reports on kernel message are still left, can be turned on/off via xrun_debug proc like before. But the bit 3, 4, 5 and 6 bits of xrun_debug proc are dropped by this patch. Also, along with the change, the message strings have been reformatted to be a bit more consistent. Last but not least, the hwptr reporting is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai

ALSA: Update documents about new bits of xrun_debug proc file

2010-07-08T07:01:17+00:00

Signed-off-by: Takashi Iwai

ALSA: Fix a typo in Procfile.txt

2009-12-26T17:37:44+00:00

Fix a typo in Documentation/sound/alsa/Procfile.txt Signed-off-by Masanari Iida Signed-off-by: Takashi Iwai

ALSA: pcm - Add logging of hwptr updates and interrupt updates

2009-07-23T09:09:03+00:00

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

ALSA: pcm - Update document about xrun_debug proc file

2009-06-11T14:14:11+00:00

Signed-off-by: Takashi Iwai

ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug mode

2009-05-27T09:04:30+00:00

The PCM hw_ptr jiffies check results sometimes in problems when a hardware doesn't give smooth hw_ptr updates. So far, au88x0 and some other drivers appear not working due to this strict check. However, this check is a nice debug tool, and the capability should be still kept. Hence, we disable this check now as default unless the user enables it by setting the xrun_debug mode to the specific stream via a proc file. Signed-off-by: Takashi Iwai

ALSA: hda - document the ELD proc interface

2008-11-22T10:15:45+00:00

Describe what ELD proc interface provides and how to fix incorrect values. Signed-off-by: Wu Fengguang Signed-off-by: Takashi Iwai

Fix typos in Documentation/: 'S'

2006-10-03T20:55:17+00:00

This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letter 'S'. Signed-off-by: Matt LaPlante Acked-by: Alan Cox Acked-by: Randy Dunlap Signed-off-by: Adrian Bunk