[PATCH 4.4 162/192] ASoC: atmel_ssc_dai: Dont unconditionally reset SSC on stream startup

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christoph Huber <c.huber@xxxxxxxxxxxxxxxxxx>

commit 3e103a65514c2947e53f3171b21255fbde8b60c6 upstream.

commit cbaadf0f90d6 ("ASoC: atmel_ssc_dai: refactor the startup and
shutdown") refactored code such that the SSC is reset on every
startup; this breaks duplex audio (e.g. first start audio playback,
then start record, causing the playback to stop/hang)

Fixes: cbaadf0f90d6 (ASoC: atmel_ssc_dai: refactor the startup and shutdown)
Signed-off-by: Christoph Huber <c.huber@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Meerwald-Stadler <p.meerwald@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 sound/soc/atmel/atmel_ssc_dai.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -298,8 +298,9 @@ static int atmel_ssc_startup(struct snd_
 	clk_enable(ssc_p->ssc->clk);
 	ssc_p->mck_rate = clk_get_rate(ssc_p->ssc->clk);
 
-	/* Reset the SSC to keep it at a clean status */
-	ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
+	/* Reset the SSC unless initialized to keep it in a clean state */
+	if (!ssc_p->initialized)
+		ssc_writel(ssc_p->ssc->regs, CR, SSC_BIT(CR_SWRST));
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		dir = 0;