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>

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 6268a4192d5c4a3300a5792ceb08610386b9256d..28fd9f95f9ba7d804751aa7139b8cc63c90a72a1 100644 (file)
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -281,6 +281,7 @@ struct snd_pcm_runtime {
        unsigned long hw_ptr_jiffies;   /* Time when hw_ptr is updated */
        unsigned long hw_ptr_buffer_jiffies; /* buffer time in jiffies */
        snd_pcm_sframes_t delay;        /* extra delay; typically FIFO size */
+       u64 hw_ptr_wrap;                /* offset for hw_ptr due to boundary wrap-around */
 
        /* -- HW params -- */
        snd_pcm_access_t access;        /* access mode */

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index f42c10a43315afdbe3761e6ef86d4fe220387124..3dc029e106a25af795f3b18f027bc4af5114197f 100644 (file)
--- 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;
 }