Added check of usbcan device presence on registration

diff --git a/lincan/src/usbcan.c b/lincan/src/usbcan.c
index 1be7a9031225a224ae23175607bde197d09156b0..7980cc3464bd2382246d0c17ecb6bbf9aee30192 100644 (file)
--- a/lincan/src/usbcan.c
+++ b/lincan/src/usbcan.c
@@ -47,6 +47,12 @@ int usbcan_request_io(struct candevice_t *candev)
 {
        struct usbcan_usb *dev = (struct usbcan_usb*)candev->sysdevptr.anydev;
 
+       if (!dev){
+               CANMSG("Cannot register usbcan while usb device is not present.\n");
+               CANMSG("Usbcan registers automatically on device insertion.\n");
+               return -ENODEV;
+       }
+
        /* start kernel thread */
        dev->rcvthread.arg = dev;
        start_kthread(usbcan_read_kthread, &dev->rcvthread);