[PATCH 4.14 029/343] staging: bcm2835-camera: Abort probe if there is no camera

[Greg Kroah-Hartman]

From: Stefan Wahren <stefan.wahren@xxxxxxxx>

[ Upstream commit 7566f39dfdc11f8a97d5810c6e6295a88f97ef91 ]

Abort the probing of the camera driver in case there isn't a camera
actually connected to the Raspberry Pi. This solution also avoids a
NULL ptr dereference of mmal instance on driver unload.

Fixes: 7b3ad5abf027 ("staging: Import the BCM2835 MMAL-based V4L2 camera driver.")
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 .../vc04_services/bcm2835-camera/bcm2835-camera.c        | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
index 377da037f31c3..b521752d9aa01 100644
--- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
@@ -1849,6 +1849,12 @@ static int __init bm2835_mmal_init(void)
 	num_cameras = get_num_cameras(instance,
 				      resolutions,
 				      MAX_BCM2835_CAMERAS);
+
+	if (num_cameras < 1) {
+		ret = -ENODEV;
+		goto cleanup_mmal;
+	}
+
 	if (num_cameras > MAX_BCM2835_CAMERAS)
 		num_cameras = MAX_BCM2835_CAMERAS;
 
@@ -1948,6 +1954,9 @@ cleanup_gdev:
 	pr_info("%s: error %d while loading driver\n",
 		BM2835_MMAL_MODULE_NAME, ret);
 
+cleanup_mmal:
+	vchiq_mmal_finalise(instance);
+
 	return ret;
 }
 
-- 
2.20.1