Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / sound / core / pcm_lib.c

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 11446a1506dad244b2d11c447e6dc39e906427f1..a82e3756a72d8b95d49834e3ab61d08c6bf4d1d1 100644 (file)
--- 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;