V4L/DVB (8506): empress: fix control handling oops

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/saa7134/saa7134-empress.c b/drivers/media/video/saa7134/saa7134-empress.c
index 2ecfbd1..cd52d5b 100644
--- a/drivers/media/video/saa7134/saa7134-empress.c
+++ b/drivers/media/video/saa7134/saa7134-empress.c
@@ -329,6 +329,22 @@
 	return saa7134_i2c_call_saa6752(dev, VIDIOC_G_EXT_CTRLS, ctrls);
 }
 
+static int empress_g_ctrl(struct file *file, void *priv,
+					struct v4l2_control *c)
+{
+	struct saa7134_dev *dev = file->private_data;
+
+	return saa7134_g_ctrl_internal(dev, NULL, c);
+}
+
+static int empress_s_ctrl(struct file *file, void *priv,
+					struct v4l2_control *c)
+{
+	struct saa7134_dev *dev = file->private_data;
+
+	return saa7134_s_ctrl_internal(dev, NULL, c);
+}
+
 static int empress_queryctrl(struct file *file, void *priv,
 					struct v4l2_queryctrl *c)
 {
@@ -415,8 +431,8 @@
 
 	.vidioc_queryctrl		= empress_queryctrl,
 	.vidioc_querymenu		= empress_querymenu,
-	.vidioc_g_ctrl			= saa7134_g_ctrl,
-	.vidioc_s_ctrl			= saa7134_s_ctrl,
+	.vidioc_g_ctrl			= empress_g_ctrl,
+	.vidioc_s_ctrl			= empress_s_ctrl,
 };
 
 /* ----------------------------------------------------------- */
diff --git a/drivers/media/video/saa7134/saa7134-video.c b/drivers/media/video/saa7134/saa7134-video.c
index 5e9cfc8..eb82489 100644
--- a/drivers/media/video/saa7134/saa7134-video.c
+++ b/drivers/media/video/saa7134/saa7134-video.c
@@ -1112,10 +1112,8 @@
 
 /* ------------------------------------------------------------------ */
 
-int saa7134_g_ctrl(struct file *file, void *priv, struct v4l2_control *c)
+int saa7134_g_ctrl_internal(struct saa7134_dev *dev, struct saa7134_fh *fh, struct v4l2_control *c)
 {
-	struct saa7134_fh *fh = priv;
-	struct saa7134_dev *dev = fh->dev;
 	const struct v4l2_queryctrl* ctrl;
 
 	ctrl = ctrl_by_id(c->id);
@@ -1160,20 +1158,31 @@
 	}
 	return 0;
 }
-EXPORT_SYMBOL_GPL(saa7134_g_ctrl);
+EXPORT_SYMBOL_GPL(saa7134_g_ctrl_internal);
 
-int saa7134_s_ctrl(struct file *file, void *f, struct v4l2_control *c)
+static int saa7134_g_ctrl(struct file *file, void *priv, struct v4l2_control *c)
+{
+	struct saa7134_fh *fh = priv;
+
+	return saa7134_g_ctrl_internal(fh->dev, fh, c);
+}
+
+int saa7134_s_ctrl_internal(struct saa7134_dev *dev,  struct saa7134_fh *fh, struct v4l2_control *c)
 {
 	const struct v4l2_queryctrl* ctrl;
-	struct saa7134_fh *fh = f;
-	struct saa7134_dev *dev = fh->dev;
 	unsigned long flags;
 	int restart_overlay = 0;
-	int err = -EINVAL;
+	int err;
 
-	err = v4l2_prio_check(&dev->prio, &fh->prio);
-	if (0 != err)
-		return err;
+	/* When called from the empress code fh == NULL.
+	   That needs to be fixed somehow, but for now this is
+	   good enough. */
+	if (fh) {
+		err = v4l2_prio_check(&dev->prio, &fh->prio);
+		if (0 != err)
+			return err;
+	}
+	err = -EINVAL;
 
 	mutex_lock(&dev->lock);
 
@@ -1274,7 +1283,14 @@
 	mutex_unlock(&dev->lock);
 	return err;
 }
-EXPORT_SYMBOL_GPL(saa7134_s_ctrl);
+EXPORT_SYMBOL_GPL(saa7134_s_ctrl_internal);
+
+static int saa7134_s_ctrl(struct file *file, void *f, struct v4l2_control *c)
+{
+	struct saa7134_fh *fh = f;
+
+	return saa7134_s_ctrl_internal(fh->dev, fh, c);
+}
 
 /* ------------------------------------------------------------------ */
 
diff --git a/drivers/media/video/saa7134/saa7134.h b/drivers/media/video/saa7134/saa7134.h
index ed20dd5..a0884f6 100644
--- a/drivers/media/video/saa7134/saa7134.h
+++ b/drivers/media/video/saa7134/saa7134.h
@@ -663,8 +663,8 @@
 extern struct video_device saa7134_video_template;
 extern struct video_device saa7134_radio_template;
 
-int saa7134_g_ctrl(struct file *file, void *priv, struct v4l2_control *c);
-int saa7134_s_ctrl(struct file *file, void *f, struct v4l2_control *c);
+int saa7134_s_ctrl_internal(struct saa7134_dev *dev,  struct saa7134_fh *fh, struct v4l2_control *c);
+int saa7134_g_ctrl_internal(struct saa7134_dev *dev,  struct saa7134_fh *fh, struct v4l2_control *c);
 int saa7134_queryctrl(struct file *file, void *priv, struct v4l2_queryctrl *c);
 
 int saa7134_videoport_init(struct saa7134_dev *dev);