Commit 3a638ff2 authored by Timur Tabi's avatar Timur Tabi Committed by Mark Brown
Browse files

ASoC: Improve pause/unpause performance in Freescale 8610 drivers 



Add support for true pause and unpause.  Without this, mplayer will drop some
audio (less than one second, but still noticeable) when pausing playback.

Remove support for PM suspend and resume from the trigger function, since the
driver doesn't support PM anyway.

Optimize the delay after starting capture.  Instead of delaying 1ms, the driver
now polls the hardware.  The new delay is shorter by over 90% yet still
effective.

Signed-off-by: default avatarTimur Tabi <timur@freescale.com>
Signed-off-by: default avatarMark Brown <broonie@opensource.wolfsonmicro.com>
parent 96deff6b

sound/soc/fsl/fsl_dma.c

+2 −1
Original line number Diff line number Diff line
@@ -142,7 +142,8 @@ static const struct snd_pcm_hardware fsl_dma_hardware = { 
	.info   		= SNDRV_PCM_INFO_INTERLEAVED |

				  SNDRV_PCM_INFO_MMAP |

				  SNDRV_PCM_INFO_MMAP_VALID |

				  SNDRV_PCM_INFO_JOINT_DUPLEX,

				  SNDRV_PCM_INFO_JOINT_DUPLEX |

				  SNDRV_PCM_INFO_PAUSE,

	.formats		= FSLDMA_PCM_FORMATS,

	.rates  		= FSLDMA_PCM_RATES,

	.rate_min       	= 5512,

sound/soc/fsl/fsl_ssi.c

+14 −9
Original line number Diff line number Diff line
@@ -464,28 +464,33 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd, 


	switch (cmd) {

	case SNDRV_PCM_TRIGGER_START:

	case SNDRV_PCM_TRIGGER_RESUME:

		clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);

	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

			clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);

			setbits32(&ssi->scr,

				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_TE);

		} else {

			clrbits32(&ssi->scr, CCSR_SSI_SCR_SSIEN);

			long timeout = jiffies + 10;



			setbits32(&ssi->scr,

				CCSR_SSI_SCR_SSIEN | CCSR_SSI_SCR_RE);



			/*

			 * I think we need this delay to allow time for the SSI

			 * to put data into its FIFO.  Without it, ALSA starts

			 * to complain about overruns.

			/* Wait until the SSI has filled its FIFO. Without this

			 * delay, ALSA complains about overruns.  When the FIFO

			 * is full, the DMA controller initiates its first

			 * transfer.  Until then, however, the DMA's DAR

			 * register is zero, which translates to an

			 * out-of-bounds pointer.  This makes ALSA think an

			 * overrun has occurred.

			 */

			mdelay(1);

			while (!(in_be32(&ssi->sisr) & CCSR_SSI_SISR_RFF0) &&

			       (jiffies < timeout));

			if (!(in_be32(&ssi->sisr) & CCSR_SSI_SISR_RFF0))

				return -EIO;

		}

		break;



	case SNDRV_PCM_TRIGGER_STOP:

	case SNDRV_PCM_TRIGGER_SUSPEND:

	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:

		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)

			clrbits32(&ssi->scr, CCSR_SSI_SCR_TE);

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