[media] em28xx-audio: fix user counting in snd_em28xx_capture_open()

dev->adev.users always needs to be increased when snd_em28xx_capture_open() is
called and succeeds.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index 05e9bd11a3ff016128e6c9dd05e1086cd454ce0e..dfdfa772eb1ee77641cc33313dd247131f4dde99 100644 (file)
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -252,7 +252,7 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
 {
        struct em28xx *dev = snd_pcm_substream_chip(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
-       int ret = 0;
+       int nonblock, ret = 0;
 
        if (!dev) {
                em28xx_err("BUG: em28xx can't find device struct."
@@ -265,15 +265,15 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
 
        dprintk("opening device and trying to acquire exclusive lock\n");
 
+       nonblock = !!(substream->f_flags & O_NONBLOCK);
+       if (nonblock) {
+               if (!mutex_trylock(&dev->lock))
+               return -EAGAIN;
+       } else
+               mutex_lock(&dev->lock);
+
        runtime->hw = snd_em28xx_hw_capture;
        if ((dev->alt == 0 || dev->is_audio_only) && dev->adev.users == 0) {
-               int nonblock = !!(substream->f_flags & O_NONBLOCK);
-
-               if (nonblock) {
-                       if (!mutex_trylock(&dev->lock))
-                               return -EAGAIN;
-               } else
-                       mutex_lock(&dev->lock);
                if (dev->is_audio_only)
                        /* vendor audio is on a separate interface */
                        dev->alt = 1;
@@ -299,11 +299,11 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
                ret = em28xx_audio_analog_set(dev);
                if (ret < 0)
                        goto err;
-
-               dev->adev.users++;
-               mutex_unlock(&dev->lock);
        }
 
+       dev->adev.users++;
+       mutex_unlock(&dev->lock);
+
        /* Dynamically adjust the period size */
        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
        snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,