[PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Jarkko Nikula]

Simultaneous audio playback and capture on OMAP1510 can cause that second
stream is stalled if there is enough delay between startup of the audio
streams.

Current implementation of the omap_mcbsp_start is starting both transmitter
and receiver at the same time and it is called only for firstly started
audio stream from the OMAP McBSP based ASoC DAI driver.

Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is
missed if there is no DMA transfer set up at that time when the first word
after McBSP startup is transmitted. The problem hasn't noted before since
later OMAPs are using level sensitive DMA request lines.

Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by
allowing to start and stop individually McBSP transmitter and receiver
logics. Then call those functions individually for both audio playback
and capture streams. This ensures that DMA transfer is setup before
transmitter or receiver is started.

Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem
analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA
request line behavior differences between the OMAP generations.

Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Tony Lindgren <tony@atomide.com>
---
 arch/arm/plat-omap/include/mach/mcbsp.h |    4 +-
 arch/arm/plat-omap/mcbsp.c              |   50 +++++++++++++++++++-----------
 sound/soc/omap/omap-mcbsp.c             |   10 +++---
 3 files changed, 39 insertions(+), 25 deletions(-)

diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h
index bb154ea..57249bb 100644
--- a/arch/arm/plat-omap/include/mach/mcbsp.h
+++ b/arch/arm/plat-omap/include/mach/mcbsp.h
@@ -387,8 +387,8 @@ void omap_mcbsp_register_board_cfg(struct omap_mcbsp_platform_data *config,
 void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg * config);
 int omap_mcbsp_request(unsigned int id);
 void omap_mcbsp_free(unsigned int id);
-void omap_mcbsp_start(unsigned int id);
-void omap_mcbsp_stop(unsigned int id);
+void omap_mcbsp_start(unsigned int id, int tx, int rx);
+void omap_mcbsp_stop(unsigned int id, int tx, int rx);
 void omap_mcbsp_xmit_word(unsigned int id, u32 word);
 u32 omap_mcbsp_recv_word(unsigned int id);
 
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index efa0e01..a3d2313 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -328,14 +328,15 @@ void omap_mcbsp_free(unsigned int id)
 EXPORT_SYMBOL(omap_mcbsp_free);
 
 /*
- * Here we start the McBSP, by enabling the sample
- * generator, both transmitter and receivers,
- * and the frame sync.
+ * Here we start the McBSP, by enabling transmitter, receiver or both.
+ * If no transmitter or receiver is active prior calling, then sample-rate
+ * generator and frame sync are started.
  */
-void omap_mcbsp_start(unsigned int id)
+void omap_mcbsp_start(unsigned int id, int tx, int rx)
 {
 	struct omap_mcbsp *mcbsp;
 	void __iomem *io_base;
+	int idle;
 	u16 w;
 
 	if (!omap_mcbsp_check_valid_id(id)) {
@@ -348,32 +349,40 @@ void omap_mcbsp_start(unsigned int id)
 	mcbsp->rx_word_length = (OMAP_MCBSP_READ(io_base, RCR1) >> 5) & 0x7;
 	mcbsp->tx_word_length = (OMAP_MCBSP_READ(io_base, XCR1) >> 5) & 0x7;
 
-	/* Start the sample generator */
-	w = OMAP_MCBSP_READ(io_base, SPCR2);
-	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
+	idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
+		  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
+
+	if (idle) {
+		/* Start the sample generator */
+		w = OMAP_MCBSP_READ(io_base, SPCR2);
+		OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
+	}
 
 	/* Enable transmitter and receiver */
 	w = OMAP_MCBSP_READ(io_base, SPCR2);
-	OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1);
+	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (tx & 1));
 
 	w = OMAP_MCBSP_READ(io_base, SPCR1);
-	OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1);
+	OMAP_MCBSP_WRITE(io_base, SPCR1, w | (rx & 1));
 
 	udelay(100);
 
-	/* Start frame sync */
-	w = OMAP_MCBSP_READ(io_base, SPCR2);
-	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
+	if (idle) {
+		/* Start frame sync */
+		w = OMAP_MCBSP_READ(io_base, SPCR2);
+		OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
+	}
 
 	/* Dump McBSP Regs */
 	omap_mcbsp_dump_reg(id);
 }
 EXPORT_SYMBOL(omap_mcbsp_start);
 
-void omap_mcbsp_stop(unsigned int id)
+void omap_mcbsp_stop(unsigned int id, int tx, int rx)
 {
 	struct omap_mcbsp *mcbsp;
 	void __iomem *io_base;
+	int idle;
 	u16 w;
 
 	if (!omap_mcbsp_check_valid_id(id)) {
@@ -386,15 +395,20 @@ void omap_mcbsp_stop(unsigned int id)
 
 	/* Reset transmitter */
 	w = OMAP_MCBSP_READ(io_base, SPCR2);
-	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1));
+	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(tx & 1));
 
 	/* Reset receiver */
 	w = OMAP_MCBSP_READ(io_base, SPCR1);
-	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(1));
+	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(rx & 1));
 
-	/* Reset the sample rate generator */
-	w = OMAP_MCBSP_READ(io_base, SPCR2);
-	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
+	idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
+		  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
+
+	if (idle) {
+		/* Reset the sample rate generator */
+		w = OMAP_MCBSP_READ(io_base, SPCR2);
+		OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
+	}
 }
 EXPORT_SYMBOL(omap_mcbsp_stop);
 
diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index a5d46a7..6a837ff 100644
--- a/sound/soc/omap/omap-mcbsp.c
+++ b/sound/soc/omap/omap-mcbsp.c
@@ -183,21 +183,21 @@ static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd,
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
 	struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data);
-	int err = 0;
+	int err = 0, play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-		if (!mcbsp_data->active++)
-			omap_mcbsp_start(mcbsp_data->bus_id);
+		mcbsp_data->active++;
+		omap_mcbsp_start(mcbsp_data->bus_id, play, !play);
 		break;
 
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-		if (!--mcbsp_data->active)
-			omap_mcbsp_stop(mcbsp_data->bus_id);
+		omap_mcbsp_stop(mcbsp_data->bus_id, play, !play);
+		mcbsp_data->active--;
 		break;
 	default:
 		err = -EINVAL;
-- 
1.6.3.3

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Tony Lindgren]

* Jarkko Nikula <jhnikula@gmail.com> [090807 09:59]:
> Simultaneous audio playback and capture on OMAP1510 can cause that second
> stream is stalled if there is enough delay between startup of the audio
> streams.
> 
> Current implementation of the omap_mcbsp_start is starting both transmitter
> and receiver at the same time and it is called only for firstly started
> audio stream from the OMAP McBSP based ASoC DAI driver.
> 
> Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is
> missed if there is no DMA transfer set up at that time when the first word
> after McBSP startup is transmitted. The problem hasn't noted before since
> later OMAPs are using level sensitive DMA request lines.
> 
> Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by
> allowing to start and stop individually McBSP transmitter and receiver
> logics. Then call those functions individually for both audio playback
> and capture streams. This ensures that DMA transfer is setup before
> transmitter or receiver is started.
> 
> Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem
> analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA
> request line behavior differences between the OMAP generations.
> 
> Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Cc: Tony Lindgren <tony@atomide.com>

This seems OK to me queue via the alsa list as it's mostly audio related.

Acked-by: Tony Lindgren <tony@atomide.com>




> ---
>  arch/arm/plat-omap/include/mach/mcbsp.h |    4 +-
>  arch/arm/plat-omap/mcbsp.c              |   50 +++++++++++++++++++-----------
>  sound/soc/omap/omap-mcbsp.c             |   10 +++---
>  3 files changed, 39 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h
> index bb154ea..57249bb 100644
> --- a/arch/arm/plat-omap/include/mach/mcbsp.h
> +++ b/arch/arm/plat-omap/include/mach/mcbsp.h
> @@ -387,8 +387,8 @@ void omap_mcbsp_register_board_cfg(struct omap_mcbsp_platform_data *config,
>  void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg * config);
>  int omap_mcbsp_request(unsigned int id);
>  void omap_mcbsp_free(unsigned int id);
> -void omap_mcbsp_start(unsigned int id);
> -void omap_mcbsp_stop(unsigned int id);
> +void omap_mcbsp_start(unsigned int id, int tx, int rx);
> +void omap_mcbsp_stop(unsigned int id, int tx, int rx);
>  void omap_mcbsp_xmit_word(unsigned int id, u32 word);
>  u32 omap_mcbsp_recv_word(unsigned int id);
>  
> diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
> index efa0e01..a3d2313 100644
> --- a/arch/arm/plat-omap/mcbsp.c
> +++ b/arch/arm/plat-omap/mcbsp.c
> @@ -328,14 +328,15 @@ void omap_mcbsp_free(unsigned int id)
>  EXPORT_SYMBOL(omap_mcbsp_free);
>  
>  /*
> - * Here we start the McBSP, by enabling the sample
> - * generator, both transmitter and receivers,
> - * and the frame sync.
> + * Here we start the McBSP, by enabling transmitter, receiver or both.
> + * If no transmitter or receiver is active prior calling, then sample-rate
> + * generator and frame sync are started.
>   */
> -void omap_mcbsp_start(unsigned int id)
> +void omap_mcbsp_start(unsigned int id, int tx, int rx)
>  {
>  	struct omap_mcbsp *mcbsp;
>  	void __iomem *io_base;
> +	int idle;
>  	u16 w;
>  
>  	if (!omap_mcbsp_check_valid_id(id)) {
> @@ -348,32 +349,40 @@ void omap_mcbsp_start(unsigned int id)
>  	mcbsp->rx_word_length = (OMAP_MCBSP_READ(io_base, RCR1) >> 5) & 0x7;
>  	mcbsp->tx_word_length = (OMAP_MCBSP_READ(io_base, XCR1) >> 5) & 0x7;
>  
> -	/* Start the sample generator */
> -	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
> +	idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
> +		  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
> +
> +	if (idle) {
> +		/* Start the sample generator */
> +		w = OMAP_MCBSP_READ(io_base, SPCR2);
> +		OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
> +	}
>  
>  	/* Enable transmitter and receiver */
>  	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1);
> +	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (tx & 1));
>  
>  	w = OMAP_MCBSP_READ(io_base, SPCR1);
> -	OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1);
> +	OMAP_MCBSP_WRITE(io_base, SPCR1, w | (rx & 1));
>  
>  	udelay(100);
>  
> -	/* Start frame sync */
> -	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
> +	if (idle) {
> +		/* Start frame sync */
> +		w = OMAP_MCBSP_READ(io_base, SPCR2);
> +		OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
> +	}
>  
>  	/* Dump McBSP Regs */
>  	omap_mcbsp_dump_reg(id);
>  }
>  EXPORT_SYMBOL(omap_mcbsp_start);
>  
> -void omap_mcbsp_stop(unsigned int id)
> +void omap_mcbsp_stop(unsigned int id, int tx, int rx)
>  {
>  	struct omap_mcbsp *mcbsp;
>  	void __iomem *io_base;
> +	int idle;
>  	u16 w;
>  
>  	if (!omap_mcbsp_check_valid_id(id)) {
> @@ -386,15 +395,20 @@ void omap_mcbsp_stop(unsigned int id)
>  
>  	/* Reset transmitter */
>  	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1));
> +	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(tx & 1));
>  
>  	/* Reset receiver */
>  	w = OMAP_MCBSP_READ(io_base, SPCR1);
> -	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(1));
> +	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(rx & 1));
>  
> -	/* Reset the sample rate generator */
> -	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
> +	idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
> +		  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
> +
> +	if (idle) {
> +		/* Reset the sample rate generator */
> +		w = OMAP_MCBSP_READ(io_base, SPCR2);
> +		OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
> +	}
>  }
>  EXPORT_SYMBOL(omap_mcbsp_stop);
>  
> diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
> index a5d46a7..6a837ff 100644
> --- a/sound/soc/omap/omap-mcbsp.c
> +++ b/sound/soc/omap/omap-mcbsp.c
> @@ -183,21 +183,21 @@ static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd,
>  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
>  	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
>  	struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data);
> -	int err = 0;
> +	int err = 0, play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
>  
>  	switch (cmd) {
>  	case SNDRV_PCM_TRIGGER_START:
>  	case SNDRV_PCM_TRIGGER_RESUME:
>  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> -		if (!mcbsp_data->active++)
> -			omap_mcbsp_start(mcbsp_data->bus_id);
> +		mcbsp_data->active++;
> +		omap_mcbsp_start(mcbsp_data->bus_id, play, !play);
>  		break;
>  
>  	case SNDRV_PCM_TRIGGER_STOP:
>  	case SNDRV_PCM_TRIGGER_SUSPEND:
>  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> -		if (!--mcbsp_data->active)
> -			omap_mcbsp_stop(mcbsp_data->bus_id);
> +		omap_mcbsp_stop(mcbsp_data->bus_id, play, !play);
> +		mcbsp_data->active--;
>  		break;
>  	default:
>  		err = -EINVAL;
> -- 
> 1.6.3.3
> 

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Peter Ujfalusi]

On Friday 07 August 2009 09:59:47 ext Jarkko Nikula wrote:
> Simultaneous audio playback and capture on OMAP1510 can cause that second
> stream is stalled if there is enough delay between startup of the audio
> streams.
>
> Current implementation of the omap_mcbsp_start is starting both transmitter
> and receiver at the same time and it is called only for firstly started
> audio stream from the OMAP McBSP based ASoC DAI driver.
>
> Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is
> missed if there is no DMA transfer set up at that time when the first word
> after McBSP startup is transmitted. The problem hasn't noted before since
> later OMAPs are using level sensitive DMA request lines.
>
> Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by
> allowing to start and stop individually McBSP transmitter and receiver
> logics. Then call those functions individually for both audio playback
> and capture streams. This ensures that DMA transfer is setup before
> transmitter or receiver is started.

Looks nice, but I would have done it a bit differently...

>
> Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem
> analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA
> request line behavior differences between the OMAP generations.
>
> Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Cc: Tony Lindgren <tony@atomide.com>
> ---
>  arch/arm/plat-omap/include/mach/mcbsp.h |    4 +-
>  arch/arm/plat-omap/mcbsp.c              |   50
> +++++++++++++++++++----------- sound/soc/omap/omap-mcbsp.c             |  
> 10 +++---
>  3 files changed, 39 insertions(+), 25 deletions(-)
>
> diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h
> b/arch/arm/plat-omap/include/mach/mcbsp.h index bb154ea..57249bb 100644
> --- a/arch/arm/plat-omap/include/mach/mcbsp.h
> +++ b/arch/arm/plat-omap/include/mach/mcbsp.h
> @@ -387,8 +387,8 @@ void omap_mcbsp_register_board_cfg(struct
> omap_mcbsp_platform_data *config, void omap_mcbsp_config(unsigned int id,
> const struct omap_mcbsp_reg_cfg * config); int omap_mcbsp_request(unsigned
> int id);
>  void omap_mcbsp_free(unsigned int id);
> -void omap_mcbsp_start(unsigned int id);
> -void omap_mcbsp_stop(unsigned int id);
> +void omap_mcbsp_start(unsigned int id, int tx, int rx);
> +void omap_mcbsp_stop(unsigned int id, int tx, int rx);

void omap_mcbsp_start(unsigned int id, int dir);
void omap_mcbsp_stop(unsigned int id, int dir);

>  void omap_mcbsp_xmit_word(unsigned int id, u32 word);
>  u32 omap_mcbsp_recv_word(unsigned int id);
>
> diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
> index efa0e01..a3d2313 100644
> --- a/arch/arm/plat-omap/mcbsp.c
> +++ b/arch/arm/plat-omap/mcbsp.c
> @@ -328,14 +328,15 @@ void omap_mcbsp_free(unsigned int id)
>  EXPORT_SYMBOL(omap_mcbsp_free);
>
>  /*
> - * Here we start the McBSP, by enabling the sample
> - * generator, both transmitter and receivers,
> - * and the frame sync.
> + * Here we start the McBSP, by enabling transmitter, receiver or both.
> + * If no transmitter or receiver is active prior calling, then sample-rate
> + * generator and frame sync are started.

 * dir == 0: tx
 * dir == 1: rx

>   */
> -void omap_mcbsp_start(unsigned int id)
> +void omap_mcbsp_start(unsigned int id, int tx, int rx)

void omap_mcbsp_start(unsigned int id, int dir)

>  {
>  	struct omap_mcbsp *mcbsp;
>  	void __iomem *io_base;
> +	int idle;
>  	u16 w;

...

>  	/* Enable transmitter and receiver */
>  	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1);
> +	OMAP_MCBSP_WRITE(io_base, SPCR2, w | (tx & 1));
>
>  	w = OMAP_MCBSP_READ(io_base, SPCR1);
> -	OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1);
> +	OMAP_MCBSP_WRITE(io_base, SPCR1, w | (rx & 1));

	if (dir) {
		/* RX: Enable receiver */
	  	w = OMAP_MCBSP_READ(io_base, SPCR1);
		OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1);
	} else {
		/* TX: Enable transmitter */
	  	w = OMAP_MCBSP_READ(io_base, SPCR2);
		OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1);
	}

>  	udelay(100);

...

> -void omap_mcbsp_stop(unsigned int id)
> +void omap_mcbsp_stop(unsigned int id, int tx, int rx)

void omap_mcbsp_stop(unsigned int id, int dir)

>  {
>  	struct omap_mcbsp *mcbsp;
>  	void __iomem *io_base;
> +	int idle;
>  	u16 w;
>
>  	if (!omap_mcbsp_check_valid_id(id)) {
> @@ -386,15 +395,20 @@ void omap_mcbsp_stop(unsigned int id)
>
>  	/* Reset transmitter */
>  	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1));
> +	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(tx & 1));
>
>  	/* Reset receiver */
>  	w = OMAP_MCBSP_READ(io_base, SPCR1);
> -	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(1));
> +	OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(rx & 1));

	if (dir) {
	  	/* RX: Reset receiver */
	  	w = OMAP_MCBSP_READ(io_base, SPCR1);
		OMAP_MCBSP_WRITE(io_base, SPCR1, w | ~(1));
	} else {
		/* TX: Reset transmitter */
	  	w = OMAP_MCBSP_READ(io_base, SPCR2);
		OMAP_MCBSP_WRITE(io_base, SPCR2, w | ~(1));
	}


> -	/* Reset the sample rate generator */
> -	w = OMAP_MCBSP_READ(io_base, SPCR2);
> -	OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
> +	idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
> +		  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
> +
> +	if (idle) {
> +		/* Reset the sample rate generator */
> +		w = OMAP_MCBSP_READ(io_base, SPCR2);
> +		OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
> +	}
>  }
>  EXPORT_SYMBOL(omap_mcbsp_stop);
>
> diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
> index a5d46a7..6a837ff 100644
> --- a/sound/soc/omap/omap-mcbsp.c
> +++ b/sound/soc/omap/omap-mcbsp.c
> @@ -183,21 +183,21 @@ static int omap_mcbsp_dai_trigger(struct
> snd_pcm_substream *substream, int cmd, struct snd_soc_pcm_runtime *rtd =
> substream->private_data;
>  	struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
>  	struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data);
> -	int err = 0;
> +	int err = 0, play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);

no need for this change.

>
>  	switch (cmd) {
>  	case SNDRV_PCM_TRIGGER_START:
>  	case SNDRV_PCM_TRIGGER_RESUME:
>  	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> -		if (!mcbsp_data->active++)
> -			omap_mcbsp_start(mcbsp_data->bus_id);
> +		mcbsp_data->active++;
> +		omap_mcbsp_start(mcbsp_data->bus_id, play, !play);

		omap_mcbsp_start(mcbsp_data->bus_id, substream->stream);

>  		break;
>
>  	case SNDRV_PCM_TRIGGER_STOP:
>  	case SNDRV_PCM_TRIGGER_SUSPEND:
>  	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> -		if (!--mcbsp_data->active)
> -			omap_mcbsp_stop(mcbsp_data->bus_id);
> +		omap_mcbsp_stop(mcbsp_data->bus_id, play, !play);

		omap_mcbsp_stop(mcbsp_data->bus_id, substream->stream);


> +		mcbsp_data->active--;
>  		break;
>  	default:
>  		err = -EINVAL;

-- 
Péter

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Jarkko Nikula]

On Fri, 7 Aug 2009 11:30:54 +0300
Peter Ujfalusi <peter.ujfalusi@nokia.com> wrote:

> Looks nice, but I would have done it a bit differently...
> 
...
> > -void omap_mcbsp_start(unsigned int id);
> > -void omap_mcbsp_stop(unsigned int id);
> > +void omap_mcbsp_start(unsigned int id, int tx, int rx);
> > +void omap_mcbsp_stop(unsigned int id, int tx, int rx);
> 
> void omap_mcbsp_start(unsigned int id, int dir);
> void omap_mcbsp_stop(unsigned int id, int dir);
> 
Valid point and cleans up a bit the ALSA SoC part of the patch.
However I didn't want to limit this generic arch/arm/plat-omap/mcbsp.c
into audio use case only. My change still allows to start transmitter
and receiver exactly at the same time. Might be worth if the
generic McBSP driver is used for something else than audio.


-- 
Jarkko

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Peter Ujfalusi]

On Friday 07 August 2009 11:47:57 ext Jarkko Nikula wrote:
> On Fri, 7 Aug 2009 11:30:54 +0300
>
> Peter Ujfalusi <peter.ujfalusi@nokia.com> wrote:
> > Looks nice, but I would have done it a bit differently...
>
> ...
>
> > > -void omap_mcbsp_start(unsigned int id);
> > > -void omap_mcbsp_stop(unsigned int id);
> > > +void omap_mcbsp_start(unsigned int id, int tx, int rx);
> > > +void omap_mcbsp_stop(unsigned int id, int tx, int rx);
> >
> > void omap_mcbsp_start(unsigned int id, int dir);
> > void omap_mcbsp_stop(unsigned int id, int dir);
>
> Valid point and cleans up a bit the ALSA SoC part of the patch.
> However I didn't want to limit this generic arch/arm/plat-omap/mcbsp.c
> into audio use case only. My change still allows to start transmitter
> and receiver exactly at the same time. Might be worth if the
> generic McBSP driver is used for something else than audio.

Good point.

-- 
Péter

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Peter Ujfalusi]

On Friday 07 August 2009 09:59:47 ext Jarkko Nikula wrote:
> Simultaneous audio playback and capture on OMAP1510 can cause that second
> stream is stalled if there is enough delay between startup of the audio
> streams.
>
> Current implementation of the omap_mcbsp_start is starting both transmitter
> and receiver at the same time and it is called only for firstly started
> audio stream from the OMAP McBSP based ASoC DAI driver.
>
> Since DMA request lines on OMAP1510 are edge sensitive, the DMA request is
> missed if there is no DMA transfer set up at that time when the first word
> after McBSP startup is transmitted. The problem hasn't noted before since
> later OMAPs are using level sensitive DMA request lines.
>
> Fix the problem by changing API of omap_mcbsp_start and omap_mcbsp_stop by
> allowing to start and stop individually McBSP transmitter and receiver
> logics. Then call those functions individually for both audio playback
> and capture streams. This ensures that DMA transfer is setup before
> transmitter or receiver is started.
>
> Thanks to Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> for detailed problem
> analysis and Peter Ujfalusi <peter.ujfalusi@nokia.com> for info about DMA
> request line behavior differences between the OMAP generations.
>
> Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
> Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
> Cc: Tony Lindgren <tony@atomide.com>
> ---
>  arch/arm/plat-omap/include/mach/mcbsp.h |    4 +-
>  arch/arm/plat-omap/mcbsp.c              |   50
> +++++++++++++++++++----------- sound/soc/omap/omap-mcbsp.c             |  
> 10 +++---
>  3 files changed, 39 insertions(+), 25 deletions(-)

Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>

Re: [PATCH][2.6.31-rc5] ARM: OMAP: McBSP: Fix ASoC on OMAP1510 by fixing API of omap_mcbsp_start/stop

[Mark Brown]

On Fri, Aug 07, 2009 at 09:59:47AM +0300, Jarkko Nikula wrote:
> Simultaneous audio playback and capture on OMAP1510 can cause that second
> stream is stalled if there is enough delay between startup of the audio
> streams.

Applied, thanks.