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;