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| author | Takashi Iwai <tiwai@suse.de> | 2009-05-27 10:53:33 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-05-27 11:04:30 +0200 |
| commit | c87d9732004b3f8fd82d729f12ccfb96c0df279e (patch) | |
| tree | f265b35a8c34fa7d0bc41c46b519b330a4d68e8e | |
| parent | 6af3fb72d2437239e5eb13a59e95dc43ccab3e8f (diff) | |
| download | linux-c87d9732004b3f8fd82d729f12ccfb96c0df279e.tar.gz linux-c87d9732004b3f8fd82d729f12ccfb96c0df279e.tar.bz2 linux-c87d9732004b3f8fd82d729f12ccfb96c0df279e.zip | |
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>
| -rw-r--r-- | Documentation/sound/alsa/Procfile.txt | 5 | ||||
| -rw-r--r-- | sound/core/pcm_lib.c | 9 |
2 files changed, 13 insertions, 1 deletions
diff --git a/Documentation/sound/alsa/Procfile.txt b/Documentation/sound/alsa/Procfile.txt index bba2dbb79d81..cfac20cf9e33 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. diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 3eea98a4e65a..d659995ac3ac 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -249,6 +249,11 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream) new_hw_ptr = hw_base + pos; } } + + /* Do jiffies check only in xrun_debug mode */ + if (!xrun_debug(substream)) + goto no_jiffies_check; + /* Skip the jiffies check for hardwares with BATCH flag. * Such hardware usually just increases the position at each IRQ, * thus it can't give any strange position. @@ -336,7 +341,9 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream) hw_base = 0; new_hw_ptr = hw_base + pos; } - if (((delta * HZ) / runtime->rate) > jdelta + HZ/100) { + /* Do jiffies check only in xrun_debug mode */ + if (xrun_debug(substream) && + ((delta * HZ) / runtime->rate) > jdelta + HZ/100) { hw_ptr_error(substream, "hw_ptr skipping! " "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu)\n", |