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ALSA: core: keep track of boundary wrap-around

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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>
This commit is contained in:
Pierre-Louis Bossart 2012-10-22 16:42:14 -05:00 committed by Takashi Iwai
parent 86a778a78d
commit 0e8014d772
2 changed files with 21 additions and 5 deletions
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1
include/sound/pcm.h
View File

@ -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 */

25
sound/core/pcm_lib.c
View File

@ -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;
}