On Wed, 08 Jul 2015 12:10:34 +0200, Pierre-Louis Bossart wrote:
When appl_ptr is updated let low-level driver know.
This is only enabled when the NO_REWIND hardware flag is used, so that the low-level driver/hardware to opportunistically pre-fetch data.
FIXME: should we rely on .ack for this? Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Hmm, OK, so the forward is allowed but with workarounds... But then why rewind won't work in a similar way? DSP might be able to cancel some of inflight data.
In other words, I see no reason to strict notify callback only for no_rewinds. This is an optional ops in anyway.
Also, I find the name "notify" a bit too ambiguous. In this case, it's notifying the applptr change. So, a name related with the function would be more understandable.
thanks,
Takashi
include/sound/pcm.h | 2 ++ sound/core/pcm_native.c | 18 +++++++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 25310b7..d5eff03 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -87,6 +87,8 @@ 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 (*notify)(struct snd_pcm_substream *substream);
- /* FIXME: what's the difference between ack and notify ? */
};
/* diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index a70e52d..dd519b8 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -2565,6 +2565,10 @@ 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 (runtime->no_rewinds && substream->ops->notify)
substream->ops->notify(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2614,6 +2618,10 @@ 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 (runtime->no_rewinds && substream->ops->notify)
substream->ops->notify(substream);- __end: snd_pcm_stream_unlock_irq(substream); return ret;
@@ -2713,8 +2721,16 @@ 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)) {
/* FIXME: this code is used by mmap_commit, should it handle boundary* wrap-around as done for read/write in pcm_lib.c*/- control->appl_ptr = sync_ptr.c.control.appl_ptr;
/* if supported, let low-level driver know about appl_ptr change */if (runtime->no_rewinds && substream->ops->notify)substream->ops->notify(substream);- } else sync_ptr.c.control.appl_ptr = control->appl_ptr; if (!(sync_ptr.flags & SNDRV_PCM_SYNC_PTR_AVAIL_MIN))
-- 1.9.1
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