V4L/DVB (7537): cx88/saa7134: Fix: avoid OOPS on module unload

If frontend is not attached, both cx88-dvb and saa7134-dvb don't
register DVB. However, dvb unregister were inconditionally called.

Due to that, an OOPS is generated.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

2 files changed, 4 insertions, 2 deletions

diff --git a/drivers/media/video/cx88/cx88-dvb.c b/drivers/media/video/cx88/cx88-dvb.c
index 8fc929eb47ba..e83d9869e68b 100644
--- a/drivers/media/video/cx88/cx88-dvb.c
+++ b/drivers/media/video/cx88/cx88-dvb.c
@@ -951,7 +951,8 @@ static int cx8802_dvb_remove(struct cx8802_driver *drv)
         struct cx8802_dev *dev = drv->core->dvbdev;
 
         /* dvb */
-        videobuf_dvb_unregister(&dev->dvb);
+        if (dev->dvb.frontend)
+                videobuf_dvb_unregister(&dev->dvb);
 
         vp3054_i2c_remove(dev);
 
diff --git a/drivers/media/video/saa7134/saa7134-dvb.c b/drivers/media/video/saa7134/saa7134-dvb.c
index 5c84f45ecbe2..e5c3569dd2c8 100644
--- a/drivers/media/video/saa7134/saa7134-dvb.c
+++ b/drivers/media/video/saa7134/saa7134-dvb.c
@@ -1302,7 +1302,8 @@ static int dvb_fini(struct saa7134_dev *dev)
                         }
                 }
         }
-        videobuf_dvb_unregister(&dev->dvb);
+        if (dev->dvb.frontend)
+                videobuf_dvb_unregister(&dev->dvb);
         return 0;
 }