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

From: Greg Kroah-Hartman
Date: Fri Jan 24 2020 - 04:45:06 EST


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