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| author | Koro Chen <koro.chen@mediatek.com> | 2015-05-13 17:39:03 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2015-05-19 10:32:29 +0300 |
| commit | 13a988396cab68e6c6afd33e461a9e52ce23ff63 (patch) | |
| tree | 546fd85f5d70daee71117ae79a1a7cb556ac6881 | |
| parent | 5a6cc82171dba297ceab49cda47f2bf5616f87b3 (diff) | |
| download | linux-13a988396cab68e6c6afd33e461a9e52ce23ff63.tar.xz | |
ALSA: pcm: Modify double acknowledged interrupts check condition
Currently in snd_pcm_update_hw_ptr0 during interrupt,
we consider there were double acknowledged interrupts when:
1. HW reported pointer is smaller than expected, and
2. Time from last update time (hdelta) is over half a buffer time.
However, when HW reported pointer is only a few bytes smaller than
expected, and when hdelta is just a little larger than half a buffer time
(e.g. ping-pong buffer), it wrongly treats this IRQ as double acknowledged.
The condition #2 uses jiffies, but jiffies is not high resolution
since it is integer. We should consider jiffies inaccuracy.
Signed-off-by: Koro Chen <koro.chen@mediatek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/core/pcm_lib.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index ac6b33f3779c..7d45645f10ba 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -339,7 +339,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream, if (delta > new_hw_ptr) { /* check for double acknowledged interrupts */ hdelta = curr_jiffies - runtime->hw_ptr_jiffies; - if (hdelta > runtime->hw_ptr_buffer_jiffies/2) { + if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) { hw_base += runtime->buffer_size; if (hw_base >= runtime->boundary) { hw_base = 0; |