From 471e3dec3abe2d41e8c742046353fcb01bc2459e Mon Sep 17 00:00:00 2001 From: Janusz Krzysztofik Date: Tue, 11 Aug 2009 21:44:29 +0200 Subject: [PATCH] ASoC: OMAP: Enhance OMAP1510 DMA progress software counter Enhance period_index accuracy, particularly just before buffer rewind, by making use of DMA interrupt status flags in addition to simply counting up interrupts. Created against linux-2.6.31-rc5. Tested on Amstrad Delta. Signed-off-by: Janusz Krzysztofik Acked-by: Jarkko Nikula Signed-off-by: Mark Brown --- sound/soc/omap/omap-pcm.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c index 3e3a9d478c0d..12e14c01068e 100644 --- a/sound/soc/omap/omap-pcm.c +++ b/sound/soc/omap/omap-pcm.c @@ -68,8 +68,21 @@ static void omap_pcm_dma_irq(int ch, u16 stat, void *data) * that can be used by omap_pcm_pointer() instead. */ spin_lock_irqsave(&prtd->lock, flags); + if ((stat == OMAP_DMA_LAST_IRQ) && + (prtd->period_index == runtime->periods - 1)) { + /* we are in sync, do nothing */ + spin_unlock_irqrestore(&prtd->lock, flags); + return; + } if (prtd->period_index >= 0) { - if (++prtd->period_index == runtime->periods) { + if (stat & OMAP_DMA_BLOCK_IRQ) { + /* end of buffer reached, loop back */ + prtd->period_index = 0; + } else if (stat & OMAP_DMA_LAST_IRQ) { + /* update the counter for the last period */ + prtd->period_index = runtime->periods - 1; + } else if (++prtd->period_index >= runtime->periods) { + /* end of buffer missed? loop back */ prtd->period_index = 0; } } @@ -175,7 +188,12 @@ static int omap_pcm_prepare(struct snd_pcm_substream *substream) dma_params.frame_count = runtime->periods; omap_set_dma_params(prtd->dma_ch, &dma_params); - omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ); + if ((cpu_is_omap1510()) && + (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) + omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ | + OMAP_DMA_LAST_IRQ | OMAP_DMA_BLOCK_IRQ); + else + omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ); return 0; } -- 2.39.5