1 files changed, 31 insertions, 14 deletions

diff --git a/drivers/media/video/ov511.c b/drivers/media/video/ov511.c
index 9af5532db142..08cfd3e4ae8a 100644
--- a/drivers/media/video/ov511.c
+++ b/drivers/media/video/ov511.c
@@ -112,6 +112,8 @@ static int framedrop		= -1;
 static int fastset;
 static int force_palette;
 static int backlight;
+/* Bitmask marking allocated devices from 0 to OV511_MAX_UNIT_VIDEO */
+static unsigned long ov511_devused;
 static int unit_video[OV511_MAX_UNIT_VIDEO];
 static int remove_zeros;
 static int mirror;
@@ -5720,7 +5722,7 @@ ov51x_probe(struct usb_interface *intf, const struct usb_device_id *id)
         struct usb_device *dev = interface_to_usbdev(intf);
         struct usb_interface_descriptor *idesc;
         struct usb_ov511 *ov;
-        int i;
+        int i, rc, nr;
 
         PDEBUG(1, "probing for device...");
 
@@ -5845,33 +5847,41 @@ ov51x_probe(struct usb_interface *intf, const struct usb_device_id *id)
         ov->vdev->parent = &intf->dev;
         video_set_drvdata(ov->vdev, ov);
 
-        for (i = 0; i < OV511_MAX_UNIT_VIDEO; i++) {
-                /* Minor 0 cannot be specified; assume user wants autodetect */
-                if (unit_video[i] == 0)
-                        break;
+        mutex_lock(&ov->lock);
 
-                if (video_register_device(ov->vdev, VFL_TYPE_GRABBER,
-                        unit_video[i]) >= 0) {
-                        break;
-                }
-        }
+        /* Check to see next free device and mark as used */
+        nr = find_first_zero_bit(&ov511_devused, OV511_MAX_UNIT_VIDEO);
+
+        /* Registers device */
+        if (unit_video[nr] != 0)
+                rc = video_register_device(ov->vdev, VFL_TYPE_GRABBER,
+                                           unit_video[nr]);
+        else
+                rc = video_register_device(ov->vdev, VFL_TYPE_GRABBER, -1);
 
-        /* Use the next available one */
-        if ((ov->vdev->minor == -1) &&
-            video_register_device(ov->vdev, VFL_TYPE_GRABBER, -1) < 0) {
+        if (rc < 0) {
                 err("video_register_device failed");
+                mutex_unlock(&ov->lock);
                 goto error;
         }
 
+        /* Mark device as used */
+        ov511_devused |= 1 << nr;
+        ov->nr = nr;
+
         dev_info(&intf->dev, "Device at %s registered to minor %d\n",
                  ov->usb_path, ov->vdev->minor);
 
         usb_set_intfdata(intf, ov);
         if (ov_create_sysfs(ov->vdev)) {
                 err("ov_create_sysfs failed");
+                ov511_devused &= ~(1 << nr);
+                mutex_unlock(&ov->lock);
                 goto error;
         }
 
+        mutex_lock(&ov->lock);
+
         return 0;
 
 error:
@@ -5906,10 +5916,16 @@ ov51x_disconnect(struct usb_interface *intf)
 
         PDEBUG(3, "");
 
+        mutex_lock(&ov->lock);
         usb_set_intfdata (intf, NULL);
 
-        if (!ov)
+        if (!ov) {
+                mutex_unlock(&ov->lock);
                 return;
+        }
+
+        /* Free device number */
+        ov511_devused &= ~(1 << ov->nr);
 
         if (ov->vdev)
                 video_unregister_device(ov->vdev);
@@ -5927,6 +5943,7 @@ ov51x_disconnect(struct usb_interface *intf)
 
         ov->streaming = 0;
         ov51x_unlink_isoc(ov);
+        mutex_unlock(&ov->lock);
 
         ov->dev = NULL;