target/linux/brcm2708/patches-4.19/950-0237-staging-bcm2835-Don-t-probe-if-no-camera-is-detected.patch

   1 From 55c9d1a762b9cbb5a4c574918fb41a9cde6bb491 Mon Sep 17 00:00:00 2001
   2 From: Stefan Wahren <stefan.wahren@i2se.com>
   3 Date: Mon, 22 Oct 2018 11:09:18 +0200
   4 Subject: [PATCH 237/703] staging: bcm2835: Don't probe if no camera is
   5  detected
   6
   7 It is a waste of resources to load the camera driver in case there isn't
   8 a camera actually connected to the Raspberry Pi. This solution also
   9 avoids a NULL ptr dereference of mmal instance on driver unload.
  10
  11 Fixes: 7b3ad5abf027 ("staging: Import the BCM2835 MMAL-based V4L2 camera driver.")
  12 Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
  13 ---
  14  .../vc04_services/bcm2835-camera/bcm2835-camera.c        | 9 +++++++++
  15  1 file changed, 9 insertions(+)
  16
  17 --- a/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
  18 +++ b/drivers/staging/vc04_services/bcm2835-camera/bcm2835-camera.c
  19 @@ -1860,6 +1860,12 @@ static int bcm2835_mmal_probe(struct pla
  20         num_cameras = get_num_cameras(instance,
  21                                       resolutions,
  22                                       MAX_BCM2835_CAMERAS);
  23 +
  24 +       if (num_cameras < 1) {
  25 +               ret = -ENODEV;
  26 +               goto cleanup_mmal;
  27 +       }
  28 +
  29         if (num_cameras > MAX_BCM2835_CAMERAS)
  30                 num_cameras = MAX_BCM2835_CAMERAS;
  31
  32 @@ -1968,6 +1974,9 @@ cleanup_gdev:
  33                 gdev[i] = NULL;
  34         }
  35
  36 +cleanup_mmal:
  37 +       vchiq_mmal_finalise(instance);
  38 +
  39         return ret;
  40  }
  41