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path: root/Documentation/sound/alsa/Procfile.txt
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2014-11-04ALSA: pcm: Add xrun_injection proc entryTakashi Iwai
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 <tiwai@suse.de>
2014-11-04ALSA: pcm: Replace PCM hwptr tracking with tracepointsTakashi Iwai
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 <tiwai@suse.de>
2010-07-08ALSA: Update documents about new bits of xrun_debug proc fileTakashi Iwai
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-12-26ALSA: Fix a typo in Procfile.txtMasanari Iida
Fix a typo in Documentation/sound/alsa/Procfile.txt Signed-off-by Masanari Iida <standby24x7@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-07-23ALSA: pcm - Add logging of hwptr updates and interrupt updatesTakashi Iwai
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>
2009-06-11ALSA: pcm - Update document about xrun_debug proc fileTakashi Iwai
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2009-05-27ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug modeTakashi Iwai
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 <tiwai@suse.de>
2008-11-22ALSA: hda - document the ELD proc interfaceWu Fengguang
Describe what ELD proc interface provides and how to fix incorrect values. Signed-off-by: Wu Fengguang <wfg@linux.intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-10-03Fix typos in Documentation/: 'S'Matt LaPlante
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letter 'S'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Alan Cox <alan@redhat.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03Fix typos in Documentation/: 'Q'-'R'Matt LaPlante
This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letters 'Q'-'R'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-10-03Fix typos in Documentation/: 'D'-'E'Matt LaPlante
This patch fixes typos in various Documentation txts. This patch addresses some words starting with the letters 'D'-'E'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-01-03[ALSA] Small update of Procfile.txtTakashi Iwai
Modules: Documentation Small update of Procfile.txt for hda and usb proc files. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!