V4L/DVB (7164): em28xx-alsa: Add a missing mutex

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/em28xx/em28xx-audio.c

@@ -269,8 +269,11 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
 	dprintk("opening device and trying to acquire exclusive lock\n");
 
 	/* Sets volume, mute, etc */
+
 	dev->mute = 0;
+	mutex_lock(&dev->lock);
 	ret = em28xx_audio_analog_set(dev);
+	mutex_unlock(&dev->lock);
 	if (ret < 0)
 		goto err;
 
@@ -302,7 +305,9 @@ static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
 	dprintk("closing device\n");
 
 	dev->mute = 1;
+	mutex_lock(&dev->lock);
 	em28xx_audio_analog_set(dev);
+	mutex_unlock(&dev->lock);
 
 	if (dev->adev->users == 0 && dev->adev->shutdown == 1) {
 		dprintk("audio users: %d\n", dev->adev->users);

drivers/media/video/em28xx/em28xx.h

@@ -345,7 +345,6 @@ int em28xx_read_reg(struct em28xx *dev, u16 reg);
 int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 			  int len);
 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len);
-int em28xx_set_audio_source(struct em28xx *dev);
 int em28xx_audio_analog_set(struct em28xx *dev);
 
 int em28xx_colorlevels_set_default(struct em28xx *dev);