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authorShine Liu <shinel@foxmail.com>2009-08-25 20:05:50 +0800
committerMark Brown <broonie@opensource.wolfsonmicro.com>2009-08-25 13:09:05 +0100
commitfaf907c7ba3d7df6266366556817f2ef7314640a (patch)
tree5b89e22322e9fce532e4c78e80b52e791366bd0d /sound/soc/s3c24xx/s3c-i2s-v2.c
parentd09a2afc9359407114b7062519101f1ee2d05388 (diff)
ASoC: S3C platform: Fix s3c2410_dma_started() called at improper time
s3c24xx dma has the auto reload feature, when the the trnasfer is done, CURR_TC(DSTAT[19:0], current value of transfer count) reaches 0, and DMA ACK becomes 1, and then, TC(DCON[19:0]) will be loaded into CURR_TC. So the transmission is repeated. IRQ is issued while auto reload occurs. We change the DISRC and DCON[19:0] in the ISR, but at this time, the auto reload has been performed already. The first block is being re-transmitted by the DMA. So we need rewrite the DISRC and DCON[19:0] for the next block immediatly after the this block has been started to be transported. The function s3c2410_dma_started() is for this perpose, which is called in the form of "s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STARTED);" in s3c24xx_pcm_trigger(). But it is not correct. DMA transmission won't start until DMA REQ signal arrived, it is the time s3c24xx_snd_txctrl(1) or s3c24xx_snd_rxctrl(1) is called in s3c24xx_i2s_trigger(). In the current framework, s3c24xx_pcm_trigger() is always called before s3c24xx_pcm_trigger(). So the s3c2410_dma_started() should be called in s3c24xx_pcm_trigger() after s3c24xx_snd_txctrl(1) or s3c24xx_snd_rxctrl(1) is called in this function. However, s3c2410_dma_started() is dma related, to call this function we should provide the channel number, which is given by substream->runtime->private_data->params->channel. The private_data points to a struct s3c24xx_runtime_data object, which is define in s3c24xx_pcm.c, so s3c2410_dma_started() can't be called in s3c24xx_i2s.c Fix this by moving the call to signal the DMA started to the DAI drivers. Signed-off-by: Shine Liu <liuxian@redflag-linux.com> Signed-off-by: Shine Liu <shinel@foxmail.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound/soc/s3c24xx/s3c-i2s-v2.c')
-rw-r--r--sound/soc/s3c24xx/s3c-i2s-v2.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/sound/soc/s3c24xx/s3c-i2s-v2.c b/sound/soc/s3c24xx/s3c-i2s-v2.c
index ebfb2f63105..11d8717c9ea 100644
--- a/sound/soc/s3c24xx/s3c-i2s-v2.c
+++ b/sound/soc/s3c24xx/s3c-i2s-v2.c
@@ -387,6 +387,8 @@ static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
int capture = (substream->stream == SNDRV_PCM_STREAM_CAPTURE);
unsigned long irqs;
int ret = 0;
+ int channel = ((struct s3c24xx_pcm_dma_params *)
+ rtd->dai->cpu_dai->dma_data)->channel;
pr_debug("Entered %s\n", __func__);
@@ -416,6 +418,14 @@ static int s3c2412_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
s3c2412_snd_txctrl(i2s, 1);
local_irq_restore(irqs);
+
+ /*
+ * Load the next buffer to DMA to meet the reqirement
+ * of the auto reload mechanism of S3C24XX.
+ * This call won't bother S3C64XX.
+ */
+ s3c2410_dma_ctrl(channel, S3C2410_DMAOP_STARTED);
+
break;
case SNDRV_PCM_TRIGGER_STOP: