ALSA: core: keep track of boundary wrap-around

Keep track of boundary crossing when hw_ptr
exceeds boundary limit and wraps-around. This
will help keep track of total number
of frames played/received at the kernel level

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 20 insertions, 5 deletions

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index f42c10a43315..3dc029e106a2 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -316,6 +316,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
         unsigned long jdelta;
         unsigned long curr_jiffies;
         struct timespec curr_tstamp;
+        int crossed_boundary = 0;
 
         old_hw_ptr = runtime->status->hw_ptr;
 
@@ -360,8 +361,10 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2) {
                                 hw_base += runtime->buffer_size;
-                                if (hw_base >= runtime->boundary)
+                                if (hw_base >= runtime->boundary) {
                                         hw_base = 0;
+                                        crossed_boundary++;
+                                }
                                 new_hw_ptr = hw_base + pos;
                                 goto __delta;
                         }
@@ -371,8 +374,10 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
         /* pointer crosses the end of the ring buffer */
         if (new_hw_ptr < old_hw_ptr) {
                 hw_base += runtime->buffer_size;
-                if (hw_base >= runtime->boundary)
+                if (hw_base >= runtime->boundary) {
                         hw_base = 0;
+                        crossed_boundary++;
+                }
                 new_hw_ptr = hw_base + pos;
         }
       __delta:
@@ -410,8 +415,10 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
                 while (hdelta > xrun_threshold) {
                         delta += runtime->buffer_size;
                         hw_base += runtime->buffer_size;
-                        if (hw_base >= runtime->boundary)
+                        if (hw_base >= runtime->boundary) {
                                 hw_base = 0;
+                                crossed_boundary++;
+                        }
                         new_hw_ptr = hw_base + pos;
                         hdelta -= runtime->hw_ptr_buffer_jiffies;
                 }
@@ -456,8 +463,10 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
                 /* the delta value is small or zero in most cases */
                 while (delta > 0) {
                         new_hw_ptr += runtime->period_size;
-                        if (new_hw_ptr >= runtime->boundary)
+                        if (new_hw_ptr >= runtime->boundary) {
                                 new_hw_ptr -= runtime->boundary;
+                                crossed_boundary--;
+                        }
                         delta--;
                 }
                 /* align hw_base to buffer_size */
@@ -507,6 +516,10 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
         runtime->hw_ptr_base = hw_base;
         runtime->status->hw_ptr = new_hw_ptr;
         runtime->hw_ptr_jiffies = curr_jiffies;
+        if (crossed_boundary) {
+                snd_BUG_ON(crossed_boundary != 1);
+                runtime->hw_ptr_wrap += runtime->boundary;
+        }
         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
                 runtime->status->tstamp = curr_tstamp;
 
@@ -1661,8 +1674,10 @@ static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
         if (snd_pcm_running(substream) &&
             snd_pcm_update_hw_ptr(substream) >= 0)
                 runtime->status->hw_ptr %= runtime->buffer_size;
-        else
+        else {
                 runtime->status->hw_ptr = 0;
+                runtime->hw_ptr_wrap = 0;
+        }
         snd_pcm_stream_unlock_irqrestore(substream, flags);
         return 0;
 }