[PATCH 3.12 021/235] ALSA: hiface: Fix M2Tech hiFace driver sampling rate change

[Jiri Slaby]

From: Jussi Laako <jussi@xxxxxxxxxxxxx>

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

===============

commit 995c6a7fd9b9212abdf01160f6ce3193176be503 upstream.

Sampling rate changes after first set one are not reflected to the
hardware, while driver and ALSA think the rate has been changed.

Fix the problem by properly stopping the interface at the beginning of
prepare call, allowing new rate to be set to the hardware. This keeps
the hardware in sync with the driver.

Signed-off-by: Jussi Laako <jussi@xxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 sound/usb/hiface/pcm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/usb/hiface/pcm.c b/sound/usb/hiface/pcm.c
index c21a3df9a0df..d4d036fca6cb 100644
--- a/sound/usb/hiface/pcm.c
+++ b/sound/usb/hiface/pcm.c
@@ -445,6 +445,8 @@ static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
 
 	mutex_lock(&rt->stream_mutex);
 
+	hiface_pcm_stream_stop(rt);
+
 	sub->dma_off = 0;
 	sub->period_off = 0;
 
-- 
2.11.0