V4L/DVB (11896): em28xx: Fix for Slow Memory Leak

Test Code:  (Provided by Douglas)

v4l-dvb/v4l2-apps/test/stress-buffer.c

The audio DMA area was never being freed and would slowly leak over
time as the v4l device was opened and closed by an application.

Thanks again to Douglas for generating the test code to help locate
memory leaks!!!

Signed-off-by: Robert Krakora <rob.krakora@messagenetsystems.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c
index 0131322475bf..7bd8a70f0a0b 100644
--- a/drivers/media/video/em28xx/em28xx-audio.c
+++ b/drivers/media/video/em28xx/em28xx-audio.c
@@ -339,6 +339,11 @@ static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
         mutex_lock(&dev->lock);
         dev->adev.users--;
         em28xx_audio_analog_set(dev);
+        if (substream->runtime->dma_area) {
+                dprintk("freeing\n");
+                vfree(substream->runtime->dma_area);
+                substream->runtime->dma_area = NULL;
+        }
         mutex_unlock(&dev->lock);
 
         return 0;