Commit 0e8014d7 authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Takashi Iwai
Browse files

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: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 86a778a7

include/sound/pcm.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

sound/core/pcm_lib.c

+20 −5
Original line number Diff line number Diff line
@@ -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;

}