X-Git-Url: https://rtime.felk.cvut.cz/gitweb/can-usb1.git/blobdiff_plain/380d9d19869a224720d02404e0823e2cd370a33f..53637485d5dc14ac14527f25b658421ed9b29f7f:/lincan-0.3.3/src/usbcan.c

diff --git a/lincan-0.3.3/src/usbcan.c b/lincan-0.3.3/src/usbcan.c
index 1be7a90..7980cc3 100644
--- a/lincan-0.3.3/src/usbcan.c
+++ b/lincan-0.3.3/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);