sorry for this mess. Please ignore this one. My script made some mistake.
-Bryan
On Sat, Sep 27, 2008 at 9:49 PM, Bryan Wu <cooloney@xxxxxxxxxx> wrote:
> From: Cliff Cai <cliff.cai@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
> ---
> sound/soc/blackfin/bf5xx-ac97-pcm.c | 42 +++++++++++++++++++++++++++++-----
> sound/soc/blackfin/bf5xx-ac97.c | 1 -
> sound/soc/blackfin/bf5xx-sport.h | 2 +
> 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 51f4907..25e50d2 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 c782e31..5e5aafb 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 4c16345..fcadcc0 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;
> };
> --
> 1.5.6
>
>
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