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-rw-r--r--sound/core/pcm_lib.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 11446a1506d..a82e3756a72 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -373,6 +373,27 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
(unsigned long)new_hw_ptr,
(unsigned long)runtime->hw_ptr_base);
}
+
+ if (runtime->no_period_wakeup) {
+ /*
+ * Without regular period interrupts, we have to check
+ * 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;
+ hw_base += runtime->buffer_size;
+ if (hw_base >= runtime->boundary)
+ hw_base = 0;
+ new_hw_ptr = hw_base + pos;
+ hdelta -= runtime->hw_ptr_buffer_jiffies;
+ }
+ goto no_delta_check;
+ }
+
/* something must be really wrong */
if (delta >= runtime->buffer_size + runtime->period_size) {
hw_ptr_error(substream,
@@ -442,6 +463,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
(long)old_hw_ptr);
}
+ no_delta_check:
if (runtime->status->hw_ptr == new_hw_ptr)
return 0;