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ALSA: pcm: unify codes to operate application-side position on PCM bu…
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…ffer

In a series of recent work, ALSA PCM core got some arrangements to handle
application-side position on PCM buffer. However, relevant codes still
disperse to two translation units

This commit unifies these codes into a helper function.

Signed-off-by: Takashi Sakamoto <[email protected]>
Signed-off-by: Takashi Iwai <[email protected]>
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takaswie authored and tiwai committed Jun 12, 2017
1 parent 82e7d50 commit 66e01a5
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Showing 3 changed files with 30 additions and 27 deletions.
27 changes: 24 additions & 3 deletions sound/core/pcm_lib.c
Original file line number Diff line number Diff line change
Expand Up @@ -2101,6 +2101,27 @@ static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
}
}

/* update to the given appl_ptr and call ack callback if needed;
* when an error is returned, take back to the original value
*/
int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
snd_pcm_uframes_t appl_ptr)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
int ret;

runtime->control->appl_ptr = appl_ptr;
if (substream->ops->ack) {
ret = substream->ops->ack(substream);
if (ret < 0) {
runtime->control->appl_ptr = old_appl_ptr;
return ret;
}
}
return 0;
}

/* the common loop for read/write data */
snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
void *data, bool interleaved,
Expand Down Expand Up @@ -2220,9 +2241,9 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
appl_ptr += frames;
if (appl_ptr >= runtime->boundary)
appl_ptr -= runtime->boundary;
runtime->control->appl_ptr = appl_ptr;
if (substream->ops->ack)
substream->ops->ack(substream);
err = pcm_lib_apply_appl_ptr(substream, appl_ptr);
if (err < 0)
goto _end_unlock;

offset += frames;
size -= frames;
Expand Down
2 changes: 2 additions & 0 deletions sound/core/pcm_local.h
Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,8 @@ int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream);
int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime,
snd_pcm_hw_param_t var, u_int32_t mask);

int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream,
snd_pcm_uframes_t appl_ptr);
int snd_pcm_update_state(struct snd_pcm_substream *substream,
struct snd_pcm_runtime *runtime);
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
Expand Down
28 changes: 4 additions & 24 deletions sound/core/pcm_native.c
Original file line number Diff line number Diff line change
Expand Up @@ -2598,27 +2598,6 @@ static int do_pcm_hwsync(struct snd_pcm_substream *substream)
}
}

/* update to the given appl_ptr and call ack callback if needed;
* when an error is returned, take back to the original value
*/
static int apply_appl_ptr(struct snd_pcm_substream *substream,
snd_pcm_uframes_t appl_ptr)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t old_appl_ptr = runtime->control->appl_ptr;
int ret;

runtime->control->appl_ptr = appl_ptr;
if (substream->ops->ack) {
ret = substream->ops->ack(substream);
if (ret < 0) {
runtime->control->appl_ptr = old_appl_ptr;
return ret;
}
}
return 0;
}

/* increase the appl_ptr; returns the processed frames or a negative error */
static snd_pcm_sframes_t forward_appl_ptr(struct snd_pcm_substream *substream,
snd_pcm_uframes_t frames,
Expand All @@ -2635,7 +2614,7 @@ static snd_pcm_sframes_t forward_appl_ptr(struct snd_pcm_substream *substream,
appl_ptr = runtime->control->appl_ptr + frames;
if (appl_ptr >= (snd_pcm_sframes_t)runtime->boundary)
appl_ptr -= runtime->boundary;
ret = apply_appl_ptr(substream, appl_ptr);
ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
return ret < 0 ? ret : frames;
}

Expand All @@ -2655,7 +2634,7 @@ static snd_pcm_sframes_t rewind_appl_ptr(struct snd_pcm_substream *substream,
appl_ptr = runtime->control->appl_ptr - frames;
if (appl_ptr < 0)
appl_ptr += runtime->boundary;
ret = apply_appl_ptr(substream, appl_ptr);
ret = pcm_lib_apply_appl_ptr(substream, appl_ptr);
return ret < 0 ? ret : frames;
}

Expand Down Expand Up @@ -2783,7 +2762,8 @@ static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream,
}
snd_pcm_stream_lock_irq(substream);
if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL)) {
err = apply_appl_ptr(substream, sync_ptr.c.control.appl_ptr);
err = pcm_lib_apply_appl_ptr(substream,
sync_ptr.c.control.appl_ptr);
if (err < 0) {
snd_pcm_stream_unlock_irq(substream);
return err;
Expand Down

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