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authorAndrew Jackson <Andrew.Jackson@arm.com>2014-12-19 17:18:05 +0100
committerMark Brown <broonie@kernel.org>2014-12-22 16:05:54 +0100
commit3475c3d034d7f276a474c8bd53f44b48c8bf669d (patch)
tree97657a04139c460ae8785d09a33b3d71a6a99514 /sound/soc
parentLinux 3.19-rc1 (diff)
downloadlinux-3475c3d034d7f276a474c8bd53f44b48c8bf669d.tar.xz
linux-3475c3d034d7f276a474c8bd53f44b48c8bf669d.zip
ASoC: dwc: Ensure FIFOs are flushed to prevent channel swap
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> Cc: stable@vger.kernel.org
Diffstat (limited to 'sound/soc')
-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 b93168d4f648..4df19b57429c 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,
};