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yaml
---
r: 157764
b: refs/heads/master
c: b5d1078
h: refs/heads/master
v: v3
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Takashi Iwai committed Sep 4, 2009
1 parent 8c49388 commit f2766ca
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Showing 2 changed files with 22 additions and 9 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 30681bcf2b15a601b9460e6ddab22077998b8d4c
refs/heads/master: b5d10781731ece07bb2049e7743907194a5cc3f1
29 changes: 21 additions & 8 deletions trunk/sound/drivers/dummy.c
Original file line number Diff line number Diff line change
Expand Up @@ -207,19 +207,18 @@ struct dummy_systimer_pcm {
struct timer_list timer;
unsigned long base_time;
unsigned int frac_pos; /* fractional sample position (based HZ) */
unsigned int frac_period_rest;
unsigned int frac_buffer_size; /* buffer_size * HZ */
unsigned int frac_period_size; /* period_size * HZ */
unsigned int rate;
int elapsed;
struct snd_pcm_substream *substream;
};

static void dummy_systimer_rearm(struct dummy_systimer_pcm *dpcm)
{
unsigned long frac;

frac = dpcm->frac_pos % dpcm->frac_period_size;
dpcm->timer.expires = jiffies +
(dpcm->frac_period_size + dpcm->rate - 1) / dpcm->rate;
(dpcm->frac_period_rest + dpcm->rate - 1) / dpcm->rate;
add_timer(&dpcm->timer);
}

Expand All @@ -230,10 +229,16 @@ static void dummy_systimer_update(struct dummy_systimer_pcm *dpcm)
delta = jiffies - dpcm->base_time;
if (!delta)
return;
dpcm->base_time = jiffies;
dpcm->frac_pos += delta * dpcm->rate;
dpcm->base_time += delta;
delta *= dpcm->rate;
dpcm->frac_pos += delta;
while (dpcm->frac_pos >= dpcm->frac_buffer_size)
dpcm->frac_pos -= dpcm->frac_buffer_size;
while (dpcm->frac_period_rest <= delta) {
dpcm->elapsed++;
dpcm->frac_period_rest += dpcm->frac_period_size;
}
dpcm->frac_period_rest -= delta;
}

static int dummy_systimer_start(struct snd_pcm_substream *substream)
Expand Down Expand Up @@ -264,6 +269,8 @@ static int dummy_systimer_prepare(struct snd_pcm_substream *substream)
dpcm->rate = runtime->rate;
dpcm->frac_buffer_size = runtime->buffer_size * HZ;
dpcm->frac_period_size = runtime->period_size * HZ;
dpcm->frac_period_rest = dpcm->frac_period_size;
dpcm->elapsed = 0;

return 0;
}
Expand All @@ -272,23 +279,29 @@ static void dummy_systimer_callback(unsigned long data)
{
struct dummy_systimer_pcm *dpcm = (struct dummy_systimer_pcm *)data;
unsigned long flags;
int elapsed = 0;

spin_lock_irqsave(&dpcm->lock, flags);
dummy_systimer_update(dpcm);
dummy_systimer_rearm(dpcm);
elapsed = dpcm->elapsed;
dpcm->elapsed = 0;
spin_unlock_irqrestore(&dpcm->lock, flags);
snd_pcm_period_elapsed(dpcm->substream);
if (elapsed)
snd_pcm_period_elapsed(dpcm->substream);
}

static snd_pcm_uframes_t
dummy_systimer_pointer(struct snd_pcm_substream *substream)
{
struct dummy_systimer_pcm *dpcm = substream->runtime->private_data;
snd_pcm_uframes_t pos;

spin_lock(&dpcm->lock);
dummy_systimer_update(dpcm);
pos = dpcm->frac_pos / HZ;
spin_unlock(&dpcm->lock);
return dpcm->frac_pos / HZ;
return pos;
}

static int dummy_systimer_create(struct snd_pcm_substream *substream)
Expand Down

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