1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/media/video/cx18/cx18-dvb.c b/drivers/media/video/cx18/cx18-dvb.c
index 71ad2d1b4c2c..0ae2c2e1eab5 100644
--- a/drivers/media/video/cx18/cx18-dvb.c
+++ b/drivers/media/video/cx18/cx18-dvb.c
@@ -213,10 +213,14 @@ static int cx18_dvb_start_feed(struct dvb_demux_feed *feed)
 {
         struct dvb_demux *demux = feed->demux;
         struct cx18_stream *stream = (struct cx18_stream *) demux->priv;
-        struct cx18 *cx = stream->cx;
+        struct cx18 *cx;
         int ret;
         u32 v;
 
+        if (!stream)
+                return -EINVAL;
+
+        cx = stream->cx;
         CX18_DEBUG_INFO("Start feed: pid = 0x%x index = %d\n",
                         feed->pid, feed->index);
 
@@ -253,12 +257,10 @@ static int cx18_dvb_start_feed(struct dvb_demux_feed *feed)
         if (!demux->dmx.frontend)
                 return -EINVAL;
 
-        if (!stream)
-                return -EINVAL;
-
         mutex_lock(&stream->dvb.feedlock);
         if (stream->dvb.feeding++ == 0) {
                 CX18_DEBUG_INFO("Starting Transport DMA\n");
+                mutex_lock(&cx->serialize_lock);
                 set_bit(CX18_F_S_STREAMING, &stream->s_flags);
                 ret = cx18_start_v4l2_encode_stream(stream);
                 if (ret < 0) {
@@ -267,6 +269,7 @@ static int cx18_dvb_start_feed(struct dvb_demux_feed *feed)
                         if (stream->dvb.feeding == 0)
                                 clear_bit(CX18_F_S_STREAMING, &stream->s_flags);
                 }
+                mutex_unlock(&cx->serialize_lock);
         } else
                 ret = 0;
         mutex_unlock(&stream->dvb.feedlock);
@@ -279,17 +282,20 @@ static int cx18_dvb_stop_feed(struct dvb_demux_feed *feed)
 {
         struct dvb_demux *demux = feed->demux;
         struct cx18_stream *stream = (struct cx18_stream *)demux->priv;
-        struct cx18 *cx = stream->cx;
+        struct cx18 *cx;
         int ret = -EINVAL;
 
-        CX18_DEBUG_INFO("Stop feed: pid = 0x%x index = %d\n",
-                        feed->pid, feed->index);
-
         if (stream) {
+                cx = stream->cx;
+                CX18_DEBUG_INFO("Stop feed: pid = 0x%x index = %d\n",
+                                feed->pid, feed->index);
+
                 mutex_lock(&stream->dvb.feedlock);
                 if (--stream->dvb.feeding == 0) {
                         CX18_DEBUG_INFO("Stopping Transport DMA\n");
+                        mutex_lock(&cx->serialize_lock);
                         ret = cx18_stop_v4l2_encode_stream(stream, 0);
+                        mutex_unlock(&cx->serialize_lock);
                 } else
                         ret = 0;
                 mutex_unlock(&stream->dvb.feedlock);