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| author | Clemens Ladisch <clemens@ladisch.de> | 2010-11-18 09:53:07 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2010-11-22 08:14:17 +0100 |
| commit | 47228e48aecdbec423a1275a5e27697d47f1f912 (patch) | |
| tree | e4a90a134de790626c6da706bda1379eef7b89a6 /sound/core | |
| parent | ALSA: pcm: detect xruns in no-period-wakeup mode (diff) | |
| download | linux-47228e48aecdbec423a1275a5e27697d47f1f912.tar.xz linux-47228e48aecdbec423a1275a5e27697d47f1f912.zip | |
ALSA: pcm: optimize xrun detection in no-period-wakeup mode
Add a lightweight condition on top of the xrun checking so that we can
avoid the division when the application is calling the update function
often enough.
Suggested-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm_lib.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index e9debaabf376..fd18c3c6484f 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -380,6 +380,8 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream, * the elapsed time to detect xruns. */ jdelta = jiffies - runtime->hw_ptr_jiffies; + if (jdelta < runtime->hw_ptr_buffer_jiffies / 2) + goto no_delta_check; hdelta = jdelta - delta * HZ / runtime->rate; while (hdelta > runtime->hw_ptr_buffer_jiffies / 2 + 1) { delta += runtime->buffer_size; |