aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorCliff Cai <cliff.cai@analog.com>2008-09-27 22:32:20 +0800
committerTakashi Iwai <tiwai@suse.de>2008-10-13 02:16:30 +0200
commit6b58a82121320f96513d88032dc3495a9c6f450b (patch)
tree0290ca3031c1ec04fca96fdb303f981f7aedcac0
parent5564b14b88a5a34ea848732030fbc202a050daa6 (diff)
ALSA: ASoC Blackfin: fix bug - Audio Latency on AD1981 with MMAP enabled
With MMAP enabled (DMA mode) on the AD1981, there is +/- 250ms of delay between writing data to alsa and audio starts coming out of the AD1981. Copy more data to local buffer before starting DMA Signed-off-by: Cliff Cai <cliff.cai@analog.com> Signed-off-by: Bryan Wu <cooloney@kernel.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/soc/blackfin/bf5xx-ac97-pcm.c42
-rw-r--r--sound/soc/blackfin/bf5xx-ac97.c1
-rw-r--r--sound/soc/blackfin/bf5xx-sport.h2
3 files changed, 37 insertions, 8 deletions
diff --git a/sound/soc/blackfin/bf5xx-ac97-pcm.c b/sound/soc/blackfin/bf5xx-ac97-pcm.c
index 51f4907c4831..25e50d2ea1ec 100644
--- a/sound/soc/blackfin/bf5xx-ac97-pcm.c
+++ b/sound/soc/blackfin/bf5xx-ac97-pcm.c
@@ -56,6 +56,7 @@ static void bf5xx_mmap_copy(struct snd_pcm_substream *substream,
sport->tx_pos += runtime->period_size;
if (sport->tx_pos >= runtime->buffer_size)
sport->tx_pos %= runtime->buffer_size;
+ sport->tx_delay_pos = sport->tx_pos;
} else {
bf5xx_ac97_to_pcm(
(struct ac97_frame *)sport->rx_dma_buf + sport->rx_pos,
@@ -72,7 +73,15 @@ static void bf5xx_dma_irq(void *data)
struct snd_pcm_substream *pcm = data;
#if defined(CONFIG_SND_MMAP_SUPPORT)
struct snd_pcm_runtime *runtime = pcm->runtime;
+ struct sport_device *sport = runtime->private_data;
bf5xx_mmap_copy(pcm, runtime->period_size);
+ if (pcm->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ if (sport->once == 0) {
+ snd_pcm_period_elapsed(pcm);
+ bf5xx_mmap_copy(pcm, runtime->period_size);
+ sport->once = 1;
+ }
+ }
#endif
snd_pcm_period_elapsed(pcm);
}
@@ -114,6 +123,10 @@ static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ memset(runtime->dma_area, 0, runtime->buffer_size);
snd_pcm_lib_free_pages(substream);
return 0;
}
@@ -127,16 +140,11 @@ static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
* SPORT working in TMD mode(include AC97).
*/
#if defined(CONFIG_SND_MMAP_SUPPORT)
- size_t size = bf5xx_pcm_hardware.buffer_bytes_max
- * sizeof(struct ac97_frame) / 4;
- /*clean up intermediate buffer*/
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
- memset(sport->tx_dma_buf, 0, size);
sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
sport_config_tx_dma(sport, sport->tx_dma_buf, runtime->periods,
runtime->period_size * sizeof(struct ac97_frame));
} else {
- memset(sport->rx_dma_buf, 0, size);
sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
sport_config_rx_dma(sport, sport->rx_dma_buf, runtime->periods,
runtime->period_size * sizeof(struct ac97_frame));
@@ -164,8 +172,12 @@ static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
pr_debug("%s enter\n", __func__);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ bf5xx_mmap_copy(substream, runtime->period_size);
+ snd_pcm_period_elapsed(substream);
+ sport->tx_delay_pos = 0;
sport_tx_start(sport);
+ }
else
sport_rx_start(sport);
break;
@@ -198,7 +210,7 @@ static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
#if defined(CONFIG_SND_MMAP_SUPPORT)
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
- curr = sport->tx_pos;
+ curr = sport->tx_delay_pos;
else
curr = sport->rx_pos;
#else
@@ -237,6 +249,21 @@ static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
return ret;
}
+static int bf5xx_pcm_close(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct sport_device *sport = runtime->private_data;
+
+ pr_debug("%s enter\n", __func__);
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ sport->once = 0;
+ memset(sport->tx_dma_buf, 0, runtime->buffer_size * sizeof(struct ac97_frame));
+ } else
+ memset(sport->rx_dma_buf, 0, runtime->buffer_size * sizeof(struct ac97_frame));
+
+ return 0;
+}
+
#ifdef CONFIG_SND_MMAP_SUPPORT
static int bf5xx_pcm_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
@@ -272,6 +299,7 @@ static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
struct snd_pcm_ops bf5xx_pcm_ac97_ops = {
.open = bf5xx_pcm_open,
+ .close = bf5xx_pcm_close,
.ioctl = snd_pcm_lib_ioctl,
.hw_params = bf5xx_pcm_hw_params,
.hw_free = bf5xx_pcm_hw_free,
diff --git a/sound/soc/blackfin/bf5xx-ac97.c b/sound/soc/blackfin/bf5xx-ac97.c
index c782e311fd56..5e5aafb6485f 100644
--- a/sound/soc/blackfin/bf5xx-ac97.c
+++ b/sound/soc/blackfin/bf5xx-ac97.c
@@ -129,7 +129,6 @@ static void enqueue_cmd(struct snd_ac97 *ac97, __u16 addr, __u16 data)
struct ac97_frame *nextwrite;
sport_incfrag(sport, &nextfrag, 1);
- sport_incfrag(sport, &nextfrag, 1);
nextwrite = (struct ac97_frame *)(sport->tx_buf + \
nextfrag * sport->tx_fragsize);
diff --git a/sound/soc/blackfin/bf5xx-sport.h b/sound/soc/blackfin/bf5xx-sport.h
index 4c163454bbf8..fcadcc081f7f 100644
--- a/sound/soc/blackfin/bf5xx-sport.h
+++ b/sound/soc/blackfin/bf5xx-sport.h
@@ -123,6 +123,8 @@ struct sport_device {
int rx_pos;
unsigned int tx_buffer_size;
unsigned int rx_buffer_size;
+ int tx_delay_pos;
+ int once;
#endif
void *private_data;
};

Privacy Policy