On Fri, 30 Sep 2016 14:43:25 +0200, Subhransu S. Prusty wrote:
From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
When appl_ptr is updated let low-level driver know, e.g. to let the low-level driver/hardware pre-fetch data opportunistically.
The existing .ack callback could be used but it would need to be extended with new arguments, resulting in multiple changes in legacy code.
I wouldn't mind changing these callers. They aren't so many, after all.
Takashi
Instead a new .appl_ptr_update callback is added. The difference between .ack and .appl_ptr_update is that .ack is only called on read or write. .appl_ptr_update is called on read, write, rewind, forward or when updating the appl_ptr from userspace.
In the ALSA core, this capability is independent from the NO_REWIND hardware flag. The low-level driver may however tie both options and only use the updated appl_ptr when rewinds are disabled due to hardware limitations.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Signed-off-by: Babu, Ramesh ramesh.babu@intel.com Signed-off-by: Vinod Koul vinod.koul@intel.com Signed-off-by: Subhransu S. Prusty subhransu.s.prusty@intel.com
include/sound/pcm.h | 1 + sound/core/pcm_lib.c | 6 ++++++ sound/core/pcm_native.c | 24 +++++++++++++++++++++++- 3 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 5344c16..1accb8b 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -87,6 +87,7 @@ struct snd_pcm_ops { unsigned long offset); int (*mmap)(struct snd_pcm_substream *substream, struct vm_area_struct *vma); int (*ack)(struct snd_pcm_substream *substream);
- int (*appl_ptr_update)(struct snd_pcm_substream *substream);
};
/* diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index bb12615..1656ca9 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -2090,6 +2090,9 @@ static snd_pcm_sframes_t snd_pcm_lib_write1(struct snd_pcm_substream *substream, if (substream->ops->ack) substream->ops->ack(substream);
if (substream->ops->appl_ptr_update)substream->ops->appl_ptr_update(substream);- offset += frames; size -= frames; xfer += frames;
@@ -2322,6 +2325,9 @@ static snd_pcm_sframes_t snd_pcm_lib_read1(struct snd_pcm_substream *substream, if (substream->ops->ack) substream->ops->ack(substream);
if (substream->ops->appl_ptr_update)substream->ops->appl_ptr_update(substream);- offset += frames; size -= frames; xfer += frames;
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index be8617b..c56d4ed 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -2475,6 +2475,10 @@ static snd_pcm_sframes_t snd_pcm_playback_rewind(struct snd_pcm_substream *subst appl_ptr += runtime->boundary; runtime->control->appl_ptr = appl_ptr; ret = frames;
- if (substream->ops->appl_ptr_update)
substream->ops->appl_ptr_update(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2526,6 +2530,10 @@ static snd_pcm_sframes_t snd_pcm_capture_rewind(struct snd_pcm_substream *substr appl_ptr += runtime->boundary; runtime->control->appl_ptr = appl_ptr; ret = frames;
- if (substream->ops->appl_ptr_update)
substream->ops->appl_ptr_update(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2575,6 +2583,10 @@ static snd_pcm_sframes_t snd_pcm_playback_forward(struct snd_pcm_substream *subs appl_ptr -= runtime->boundary; runtime->control->appl_ptr = appl_ptr; ret = frames;
- if (substream->ops->appl_ptr_update)
substream->ops->appl_ptr_update(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2624,6 +2636,10 @@ static snd_pcm_sframes_t snd_pcm_capture_forward(struct snd_pcm_substream *subst appl_ptr -= runtime->boundary; runtime->control->appl_ptr = appl_ptr; ret = frames;
- if (substream->ops->appl_ptr_update)
substream->ops->appl_ptr_update(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2723,8 +2739,14 @@ static int snd_pcm_sync_ptr(struct snd_pcm_substream *substream, return err; } snd_pcm_stream_lock_irq(substream);
- if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL))
- if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_APPL)) {
/* boundary wrap-around is assumed to be handled in userspace *//* let low-level driver know about appl_ptr change */if (substream->ops->appl_ptr_update)substream->ops->appl_ptr_update(substream);- } else sync_ptr.c.control.appl_ptr = control->appl_ptr; if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
-- 1.9.1