V4L/DVB (10521): em28xx-audio: Add lock for users

Added lock for users count

Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c
index 8e9957dbdbec..38436af2164b 100644
--- a/drivers/media/video/em28xx/em28xx-audio.c
+++ b/drivers/media/video/em28xx/em28xx-audio.c
@@ -313,7 +313,9 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
                 dprintk("changing alternate number to 7\n");
         }
 
+        mutex_lock(&dev->lock);
         dev->adev.users++;
+        mutex_unlock(&dev->lock);
 
         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
         dev->adev.capture_pcm_substream = substream;
@@ -328,12 +330,12 @@ err:
 static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
 {
         struct em28xx *dev = snd_pcm_substream_chip(substream);
-        dev->adev.users--;
 
         dprintk("closing device\n");
 
         dev->mute = 1;
         mutex_lock(&dev->lock);
+        dev->adev.users--;
         em28xx_audio_analog_set(dev);
         mutex_unlock(&dev->lock);