diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 0d8565428abb..a1705ed0b844 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -91,6 +91,7 @@ static void comedi_device_init(struct comedi_device *dev)
 {
 	spin_lock_init(&dev->spinlock);
 	mutex_init(&dev->mutex);
+	init_rwsem(&dev->attach_lock);
 	dev->minor = -1;
 }
 
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index e2432471c390..70de3558c74e 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -22,6 +22,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/mutex.h>
 #include <linux/spinlock_types.h>
+#include <linux/rwsem.h>
 
 #include "comedi.h"
 
@@ -184,6 +185,7 @@ struct comedi_device {
 	bool ioenabled:1;
 	spinlock_t spinlock;
 	struct mutex mutex;
+	struct rw_semaphore attach_lock;
 
 	int n_subdevices;
 	struct comedi_subdevice *subdevices;