[PATCH 0/3] introduce device_buffer

[PATCH 0/3] introduce device_buffer

[Vinod Koul]

Old wine ina  new bottle, so here is the second attempt for adding the notion of
how devices (in my case a DSP) can buffer data and that can be used by sound
core

Vinod Koul (3):
  ALSA: pcm - introduce device_buffer
  ASoC: add device_buffer in asoc
  ASoC: mid-x86 - implement buffer query in sst_platform driver

 include/sound/pcm.h              |    1 +
 include/sound/soc-dai.h          |    6 ++++++
 include/sound/soc.h              |    7 ++++++-
 sound/core/pcm_lib.c             |   14 +++++++++++---
 sound/core/pcm_native.c          |    6 +++---
 sound/soc/mid-x86/sst_platform.c |   23 +++++++++++++++++++++++
 sound/soc/mid-x86/sst_platform.h |    4 +++-
 sound/soc/soc-pcm.c              |   13 +++++++++++++
 8 files changed, 66 insertions(+), 8 deletions(-)

-- 
1.7.9.5

[PATCH 1/3] ALSA: pcm - introduce device_buffer

[Vinod Koul]

In many modern SoCs the audio DSP can buffer the PCM ring buffer data, typically
in SRAMs or any other memry availble.
Today we have no means to represent this buffering and ALSA in some cases when
device still has to render this buffer but app_ptr is equal to hw_ptr alsa
wrongly detects an overrun

This patch tries to add a new field "device_buffer" to represent buffering done in
DSPs. This value is also used for the xrun calculations in ALSA

Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
---
 include/sound/pcm.h     |    1 +
 sound/core/pcm_lib.c    |   14 +++++++++++---
 sound/core/pcm_native.c |    6 +++---
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index c75c0d1..58e669a 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -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 */
+	snd_pcm_sframes_t device_buffer; /* buffered data in device/driver */
 
 	/* -- HW params -- */
 	snd_pcm_access_t access;	/* access mode */
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 7ae6719..1d15431 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -292,7 +292,15 @@ int snd_pcm_update_state(struct snd_pcm_substream *substream,
 			return -EPIPE;
 		}
 	} else {
-		if (avail >= runtime->stop_threshold) {
+		snd_pcm_uframes_t actual_avail;
+		if (avail < runtime->device_buffer)
+			actual_avail = avail;
+		else
+			actual_avail = avail - runtime->device_buffer;
+		if (actual_avail  >= runtime->stop_threshold) {
+			snd_printd(KERN_ERR  "avail > stop_threshold!!\n");
+			snd_printd(KERN_ERR  "actual_avail %ld, avail %ld, device_buffer %ld!!\n",
+					actual_avail, avail,  runtime->device_buffer);
 			xrun(substream);
 			return -EPIPE;
 		}
@@ -440,9 +448,9 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 	if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 		goto no_jiffies_check;
 	hdelta = delta;
-	if (hdelta < runtime->delay)
+	if (hdelta < (runtime->delay + runtime->device_buffer))
 		goto no_jiffies_check;
-	hdelta -= runtime->delay;
+	hdelta -= (runtime->delay + runtime->device_buffer);
 	jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 	if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 		delta = jdelta /
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 53b5ada..33f1afa 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -606,13 +606,13 @@ int snd_pcm_status(struct snd_pcm_substream *substream,
 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING ||
 		    runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 			status->delay = runtime->buffer_size - status->avail;
-			status->delay += runtime->delay;
+			status->delay += runtime->delay + runtime->device_buffer;
 		} else
 			status->delay = 0;
 	} else {
 		status->avail = snd_pcm_capture_avail(runtime);
 		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
-			status->delay = status->avail + runtime->delay;
+			status->delay = status->avail + runtime->delay + runtime->device_buffer;
 		else
 			status->delay = 0;
 	}
@@ -2442,7 +2442,7 @@ static int snd_pcm_delay(struct snd_pcm_substream *substream,
 			n = snd_pcm_playback_hw_avail(runtime);
 		else
 			n = snd_pcm_capture_avail(runtime);
-		n += runtime->delay;
+		n += runtime->delay + runtime->device_buffer;
 		break;
 	case SNDRV_PCM_STATE_XRUN:
 		err = -EPIPE;
-- 
1.7.9.5

[PATCH 2/3] ASoC: add device_buffer in asoc

[Vinod Koul]

Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
---
 include/sound/soc-dai.h |    6 ++++++
 include/sound/soc.h     |    7 ++++++-
 sound/soc/soc-pcm.c     |   13 +++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h
index 628db7b..b0c84df 100644
--- a/include/sound/soc-dai.h
+++ b/include/sound/soc-dai.h
@@ -182,6 +182,12 @@ struct snd_soc_dai_ops {
 	 */
 	snd_pcm_sframes_t (*delay)(struct snd_pcm_substream *,
 		struct snd_soc_dai *);
+	/*
+	 * For hardware based buffer reporting
+	 * Optional.
+	 */
+	snd_pcm_sframes_t (*buffer)(struct snd_pcm_substream *,
+		struct snd_soc_dai *);
 };
 
 /*
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 313b766..0d5046b 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -795,7 +795,12 @@ struct snd_soc_platform_driver {
 	 */
 	snd_pcm_sframes_t (*delay)(struct snd_pcm_substream *,
 		struct snd_soc_dai *);
-
+	/*
+	 * For hardware based buffer reporting
+	 * Optional.
+	 */
+	snd_pcm_sframes_t (*buffer)(struct snd_pcm_substream *,
+		struct snd_soc_dai *);
 	/* platform stream pcm ops */
 	struct snd_pcm_ops *ops;
 
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index ef22d0b..cd7b10f 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -674,6 +674,7 @@ static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	snd_pcm_uframes_t offset = 0;
 	snd_pcm_sframes_t delay = 0;
+	snd_pcm_sframes_t buffer = 0;
 
 	if (platform->driver->ops && platform->driver->ops->pointer)
 		offset = platform->driver->ops->pointer(substream);
@@ -687,7 +688,19 @@ static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
 	if (platform->driver->delay)
 		delay += platform->driver->delay(substream, codec_dai);
 
+	if (cpu_dai->driver->ops->buffer)
+		buffer += cpu_dai->driver->ops->buffer(substream, cpu_dai);
+
+	if (codec_dai->driver->ops->buffer)
+		buffer += codec_dai->driver->ops->buffer(substream, codec_dai);
+
+	if (platform->driver->buffer)
+		buffer += platform->driver->buffer(substream, codec_dai);
+
+
+
 	runtime->delay = delay;
+	runtime->device_buffer = buffer;
 
 	return offset;
 }
-- 
1.7.9.5

[PATCH 3/3] ASoC: mid-x86 - implement buffer query in sst_platform driver

[Vinod Koul]

Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
---
 sound/soc/mid-x86/sst_platform.c |   23 +++++++++++++++++++++++
 sound/soc/mid-x86/sst_platform.h |    4 +++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/sound/soc/mid-x86/sst_platform.c b/sound/soc/mid-x86/sst_platform.c
index a263cbe..ec8773f 100644
--- a/sound/soc/mid-x86/sst_platform.c
+++ b/sound/soc/mid-x86/sst_platform.c
@@ -424,6 +424,28 @@ static snd_pcm_uframes_t sst_platform_pcm_pointer
 	return stream->stream_info.buffer_ptr;
 }
 
+static snd_pcm_sframes_t sst_platform_pcm_buffer(
+		struct snd_pcm_substream *substream,
+		struct snd_soc_dai *dai)
+{
+	struct sst_runtime_stream *stream;
+	int ret_val, status;
+	struct pcm_stream_info *str_info;
+
+	stream = substream->runtime->private_data;
+	status = sst_get_stream_status(stream);
+	if (status == SST_PLATFORM_INIT)
+		return 0;
+	str_info = &stream->stream_info;
+	ret_val = stream->ops->device_control(
+				SST_SND_BUFFER_DELTA, str_info);
+	if (ret_val) {
+		pr_err("sst: error code = %d\n", ret_val);
+		return ret_val;
+	}
+	return stream->stream_info.buffer_delta;
+}
+
 static int sst_platform_pcm_hw_params(struct snd_pcm_substream *substream,
 		struct snd_pcm_hw_params *params)
 {
@@ -669,6 +691,7 @@ static struct snd_soc_platform_driver sst_soc_platform_drv = {
 	.compr_ops	= &sst_platform_compr_ops,
 	.pcm_new	= sst_pcm_new,
 	.pcm_free	= sst_pcm_free,
+	.buffer		= sst_platform_pcm_buffer,
 };
 
 static int sst_platform_probe(struct platform_device *pdev)
diff --git a/sound/soc/mid-x86/sst_platform.h b/sound/soc/mid-x86/sst_platform.h
index d61c5d5..300b45f 100644
--- a/sound/soc/mid-x86/sst_platform.h
+++ b/sound/soc/mid-x86/sst_platform.h
@@ -50,6 +50,7 @@ struct pcm_stream_info {
 	void *mad_substream;
 	void (*period_elapsed) (void *mad_substream);
 	unsigned long long buffer_ptr;
+	unsigned long long buffer_delta;
 	int sfreq;
 };
 
@@ -70,7 +71,8 @@ enum sst_controls {
 	SST_SND_BUFFER_POINTER =	0x05,
 	SST_SND_STREAM_INIT =		0x06,
 	SST_SND_START	 =		0x07,
-	SST_MAX_CONTROLS =		0x07,
+	SST_SND_BUFFER_DELTA =		0x08,
+	SST_MAX_CONTROLS =		0x08,
 };
 
 enum sst_stream_ops {
-- 
1.7.9.5

Re: [PATCH 0/3] introduce device_buffer

[Mark Brown]

On Fri, Aug 31, 2012 at 12:42:35AM +0530, Vinod Koul wrote:
> Old wine ina  new bottle, so here is the second attempt for adding the notion of
> how devices (in my case a DSP) can buffer data and that can be used by sound
> core

This all looks good for me.