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authorTakashi Iwai <tiwai@suse.de>2009-05-27 10:53:33 +0200
committerTakashi Iwai <tiwai@suse.de>2009-05-27 11:04:30 +0200
commitc87d9732004b3f8fd82d729f12ccfb96c0df279e (patch)
treef265b35a8c34fa7d0bc41c46b519b330a4d68e8e /Documentation
parent6af3fb72d2437239e5eb13a59e95dc43ccab3e8f (diff)
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ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug mode
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>
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 bba2dbb79d8..cfac20cf9e3 100644
--- a/Documentation/sound/alsa/Procfile.txt
+++ b/Documentation/sound/alsa/Procfile.txt
@@ -104,6 +104,11 @@ card*/pcm*/xrun_debug
When this value is greater than 1, the driver will show the
stack trace additionally. This may help the debugging.
+ Since 2.6.30, this option also enables the hwptr check using
+ jiffies. This detects spontaneous invalid pointer callback
+ values, but can be lead to too much corrections for a (mostly
+ buggy) hardware that doesn't give smooth pointer updates.
+
card*/pcm*/sub*/info
The general information of this PCM sub-stream.