3 files changed, 19 insertions, 4 deletions

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 0caf71e16944..2092274212b9 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -270,6 +270,7 @@ struct snd_pcm_runtime {
         snd_pcm_uframes_t hw_ptr_base;  /* Position at buffer restart */
         snd_pcm_uframes_t hw_ptr_interrupt; /* Position at interrupt time */
         unsigned long hw_ptr_jiffies;   /* Time when hw_ptr is updated */
+        snd_pcm_sframes_t delay;        /* extra delay; typically FIFO size */
 
         /* -- HW params -- */
         snd_pcm_access_t access;        /* access mode */
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index b5da656d1ece..45dc53fcfa2f 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -587,14 +587,15 @@ int snd_pcm_status(struct snd_pcm_substream *substream,
         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
                 status->avail = snd_pcm_playback_avail(runtime);
                 if (runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
-                    runtime->status->state == SNDRV_PCM_STATE_DRAINING)
+                    runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
                         status->delay = runtime->buffer_size - status->avail;
-                else
+                        status->delay += runtime->delay;
+                } else
                         status->delay = 0;
         } else {
                 status->avail = snd_pcm_capture_avail(runtime);
                 if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
-                        status->delay = status->avail;
+                        status->delay = status->avail + runtime->delay;
                 else
                         status->delay = 0;
         }
@@ -2410,6 +2411,7 @@ static int snd_pcm_delay(struct snd_pcm_substream *substream,
                         n = snd_pcm_playback_hw_avail(runtime);
                 else
                         n = snd_pcm_capture_avail(runtime);
+                n += runtime->delay;
                 break;
         case SNDRV_PCM_STATE_XRUN:
                 err = -EPIPE;
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index a6b88482637b..a8ef2cbcc03b 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -627,6 +627,7 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
         subs->hwptr_done += offs;
         if (subs->hwptr_done >= runtime->buffer_size)
                 subs->hwptr_done -= runtime->buffer_size;
+        runtime->delay += offs;
         spin_unlock_irqrestore(&subs->lock, flags);
         urb->transfer_buffer_length = offs * stride;
         if (period_elapsed)
@@ -636,12 +637,22 @@ static int prepare_playback_urb(struct snd_usb_substream *subs,
 
 /*
  * process after playback data complete
- * - nothing to do
+ * - decrease the delay count again
  */
 static int retire_playback_urb(struct snd_usb_substream *subs,
                                struct snd_pcm_runtime *runtime,
                                struct urb *urb)
 {
+        unsigned long flags;
+        int stride = runtime->frame_bits >> 3;
+        int processed = urb->transfer_buffer_length / stride;
+
+        spin_lock_irqsave(&subs->lock, flags);
+        if (processed > runtime->delay)
+                runtime->delay = 0;
+        else
+                runtime->delay -= processed;
+        spin_unlock_irqrestore(&subs->lock, flags);
         return 0;
 }
 
@@ -1520,6 +1531,7 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
         subs->hwptr_done = 0;
         subs->transfer_done = 0;
         subs->phase = 0;
+        runtime->delay = 0;
 
         /* clear urbs (to be sure) */
         deactivate_urbs(subs, 0, 1);