V4L/DVB: em28xx: fix locks during dvb init sequence

Serialize DVB initialization, to avoid it to happen while analog
initialization is still happening.

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

2 files changed, 10 insertions, 13 deletions

diff --git a/drivers/media/video/em28xx/em28xx-core.c b/drivers/media/video/em28xx/em28xx-core.c
index 258041d0be9e..d3813ed789d9 100644
--- a/drivers/media/video/em28xx/em28xx-core.c
+++ b/drivers/media/video/em28xx/em28xx-core.c
@@ -1178,21 +1178,18 @@ void em28xx_add_into_devlist(struct em28xx *dev)
  */
 
 static LIST_HEAD(em28xx_extension_devlist);
-static DEFINE_MUTEX(em28xx_extension_devlist_lock);
 
 int em28xx_register_extension(struct em28xx_ops *ops)
 {
         struct em28xx *dev = NULL;
 
         mutex_lock(&em28xx_devlist_mutex);
-        mutex_lock(&em28xx_extension_devlist_lock);
         list_add_tail(&ops->next, &em28xx_extension_devlist);
         list_for_each_entry(dev, &em28xx_devlist, devlist) {
                 if (dev)
                         ops->init(dev);
         }
         printk(KERN_INFO "Em28xx: Initialized (%s) extension\n", ops->name);
-        mutex_unlock(&em28xx_extension_devlist_lock);
         mutex_unlock(&em28xx_devlist_mutex);
         return 0;
 }
@@ -1208,10 +1205,8 @@ void em28xx_unregister_extension(struct em28xx_ops *ops)
                         ops->fini(dev);
         }
 
-        mutex_lock(&em28xx_extension_devlist_lock);
         printk(KERN_INFO "Em28xx: Removed (%s) extension\n", ops->name);
         list_del(&ops->next);
-        mutex_unlock(&em28xx_extension_devlist_lock);
         mutex_unlock(&em28xx_devlist_mutex);
 }
 EXPORT_SYMBOL(em28xx_unregister_extension);
@@ -1220,26 +1215,26 @@ void em28xx_init_extension(struct em28xx *dev)
 {
         struct em28xx_ops *ops = NULL;
 
-        mutex_lock(&em28xx_extension_devlist_lock);
+        mutex_lock(&em28xx_devlist_mutex);
         if (!list_empty(&em28xx_extension_devlist)) {
                 list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                         if (ops->init)
                                 ops->init(dev);
                 }
         }
-        mutex_unlock(&em28xx_extension_devlist_lock);
+        mutex_unlock(&em28xx_devlist_mutex);
 }
 
 void em28xx_close_extension(struct em28xx *dev)
 {
         struct em28xx_ops *ops = NULL;
 
-        mutex_lock(&em28xx_extension_devlist_lock);
+        mutex_lock(&em28xx_devlist_mutex);
         if (!list_empty(&em28xx_extension_devlist)) {
                 list_for_each_entry(ops, &em28xx_extension_devlist, next) {
                         if (ops->fini)
                                 ops->fini(dev);
                 }
         }
-        mutex_unlock(&em28xx_extension_devlist_lock);
+        mutex_unlock(&em28xx_devlist_mutex);
 }
diff --git a/drivers/media/video/em28xx/em28xx-dvb.c b/drivers/media/video/em28xx/em28xx-dvb.c
index e7b3d5371558..cf1d8c3655fc 100644
--- a/drivers/media/video/em28xx/em28xx-dvb.c
+++ b/drivers/media/video/em28xx/em28xx-dvb.c
@@ -467,6 +467,7 @@ static int dvb_init(struct em28xx *dev)
         }
         dev->dvb = dvb;
 
+        mutex_lock(&dev->lock);
         em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
         /* init frontend */
         switch (dev->model) {
@@ -590,15 +591,16 @@ static int dvb_init(struct em28xx *dev)
         if (result < 0)
                 goto out_free;
 
-        em28xx_set_mode(dev, EM28XX_SUSPEND);
         em28xx_info("Successfully loaded em28xx-dvb\n");
-        return 0;
+ret:
+        em28xx_set_mode(dev, EM28XX_SUSPEND);
+        mutex_unlock(&dev->lock);
+        return result;
 
 out_free:
-        em28xx_set_mode(dev, EM28XX_SUSPEND);
         kfree(dvb);
         dev->dvb = NULL;
-        return result;
+        goto ret;
 }
 
 static int dvb_fini(struct em28xx *dev)