V4L/DVB (10083): soc-camera: unify locking, play nicer with videobuf locking

Move mutex from host drivers to camera device object, take into account
videobuf locking.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c
index aa7efc4..c3c50de0 100644
--- a/drivers/media/video/pxa_camera.c
+++ b/drivers/media/video/pxa_camera.c
@@ -25,7 +25,6 @@
 #include <linux/version.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
-#include <linux/mutex.h>
 #include <linux/clk.h>
 
 #include <media/v4l2-common.h>
@@ -164,8 +163,6 @@
 			CICR0_PERRM | CICR0_QDM | CICR0_CDM | CICR0_SOFM | \
 			CICR0_EOFM | CICR0_FOM)
 
-static DEFINE_MUTEX(camera_lock);
-
 /*
  * Structures
  */
@@ -813,16 +810,17 @@ static irqreturn_t pxa_camera_irq(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-/* The following two functions absolutely depend on the fact, that
- * there can be only one camera on PXA quick capture interface */
+/*
+ * The following two functions absolutely depend on the fact, that
+ * there can be only one camera on PXA quick capture interface
+ * Called with .video_lock held
+ */
 static int pxa_camera_add_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);
 	struct pxa_camera_dev *pcdev = ici->priv;
 	int ret;
 
-	mutex_lock(&camera_lock);
-
 	if (pcdev->icd) {
 		ret = -EBUSY;
 		goto ebusy;
@@ -838,11 +836,10 @@ static int pxa_camera_add_device(struct soc_camera_device *icd)
 		pcdev->icd = icd;
 
 ebusy:
-	mutex_unlock(&camera_lock);
-
 	return ret;
 }
 
+/* Called with .video_lock held */
 static void pxa_camera_remove_device(struct soc_camera_device *icd)
 {
 	struct soc_camera_host *ici = to_soc_camera_host(icd->dev.parent);