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authorAndrew Jackson <Andrew.Jackson@arm.com>2014-12-19 16:18:05 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-01-16 06:59:00 -0800
commit97a3f651913ffb8e13357913d6e93fb8fbacab3a (patch)
treeec3c80906e40394ff092c1d6128951cb61e6807e /sound
parentef3a852c749491082bea51e1f0b4ee27afb2b94c (diff)
ASoC: dwc: Ensure FIFOs are flushed to prevent channel swap
commit 3475c3d034d7f276a474c8bd53f44b48c8bf669d upstream. Flush the FIFOs when the stream is prepared for use. This avoids an inadvertent swapping of the left/right channels if the FIFOs are not empty at startup. Signed-off-by: Andrew Jackson <Andrew.Jackson@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/soc/dwc/designware_i2s.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index 593a3ea12d4c..489a9abf112b 100644
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -263,6 +263,19 @@ static void dw_i2s_shutdown(struct snd_pcm_substream *substream,
snd_soc_dai_set_dma_data(dai, substream, NULL);
}
+static int dw_i2s_prepare(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ i2s_write_reg(dev->i2s_base, TXFFR, 1);
+ else
+ i2s_write_reg(dev->i2s_base, RXFFR, 1);
+
+ return 0;
+}
+
static int dw_i2s_trigger(struct snd_pcm_substream *substream,
int cmd, struct snd_soc_dai *dai)
{
@@ -294,6 +307,7 @@ static struct snd_soc_dai_ops dw_i2s_dai_ops = {
.startup = dw_i2s_startup,
.shutdown = dw_i2s_shutdown,
.hw_params = dw_i2s_hw_params,
+ .prepare = dw_i2s_prepare,
.trigger = dw_i2s_trigger,
};