[media] em28xx-audio: fix some locking issues

Those locking issues affect tvtime, causing a kernel oops/panic, due to
a race condition.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/drivers/media/video/em28xx/em28xx.h b/drivers/media/video/em28xx/em28xx.h
index 1c61a6b65d28..adb20eb6d902 100644
--- a/drivers/media/video/em28xx/em28xx.h
+++ b/drivers/media/video/em28xx/em28xx.h
@@ -25,12 +25,13 @@
 #ifndef _EM28XX_H
 #define _EM28XX_H
 
+#include <linux/workqueue.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
 #include <linux/videodev2.h>
+
 #include <media/videobuf-vmalloc.h>
 #include <media/v4l2-device.h>
-
-#include <linux/i2c.h>
-#include <linux/mutex.h>
 #include <media/ir-kbd-i2c.h>
 #include <media/ir-core.h>
 #if defined(CONFIG_VIDEO_EM28XX_DVB) || defined(CONFIG_VIDEO_EM28XX_DVB_MODULE)
@@ -184,11 +185,6 @@ enum em28xx_mode {
         EM28XX_DIGITAL_MODE,
 };
 
-enum em28xx_stream_state {
-        STREAM_OFF,
-        STREAM_INTERRUPT,
-        STREAM_ON,
-};
 
 struct em28xx;
 
@@ -463,7 +459,6 @@ struct em28xx_audio {
         struct snd_card            *sndcard;
 
         int users;
-        enum em28xx_stream_state capture_stream;
         spinlock_t slock;
 };
 
@@ -505,6 +500,10 @@ struct em28xx {
         unsigned int has_audio_class:1;
         unsigned int has_alsa_audio:1;
 
+        /* Controls audio streaming */
+        struct work_struct wq_trigger;              /* Trigger to start/stop audio for alsa module */
+         atomic_t       stream_started;      /* stream should be running if true */
+
         struct em28xx_fmt *format;
 
         struct em28xx_IR *ir;