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authorJanusz Krzysztofik <jkrzyszt@tis.icnet.pl>2009-08-11 21:44:29 +0200
committerMark Brown <broonie@opensource.wolfsonmicro.com>2009-08-17 11:00:34 +0100
commit471e3dec3abe2d41e8c742046353fcb01bc2459e (patch)
tree15bcba2e2823d5859784d4f3d2fa726435ddf7d6 /sound
parent64844a6ac8ddd586cb832fea7cf2e93e5e7e03f4 (diff)
downloadlinux-linaro-precise-471e3dec3abe2d41e8c742046353fcb01bc2459e.tar.gz
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 <jkrzyszt@tis.icnet.pl> Acked-by: Jarkko Nikula <jhnikula@gmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound')
-rw-r--r--sound/soc/omap/omap-pcm.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/sound/soc/omap/omap-pcm.c b/sound/soc/omap/omap-pcm.c
index 3e3a9d478c0..12e14c01068 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;
}