#include <linux/list.h>
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
-#include <linux/smp_lock.h>
 #include <linux/init.h>
 #include <asm/uaccess.h>
 #include <asm/atomic.h>
        if (devnum < DABUSB_MINOR || devnum >= (DABUSB_MINOR + NRDABUSB))
                return -EIO;
 
-       lock_kernel();
        s = &dabusb[devnum - DABUSB_MINOR];
 
        dbg("dabusb_open");
        while (!s->usbdev || s->opened) {
                mutex_unlock(&s->mutex);
 
-               if (file->f_flags & O_NONBLOCK) {
+               if (file->f_flags & O_NONBLOCK)
                        return -EBUSY;
-               }
                msleep_interruptible(500);
 
-               if (signal_pending (current)) {
-                       unlock_kernel();
+               if (signal_pending (current))
                        return -EAGAIN;
-               }
                mutex_lock(&s->mutex);
        }
        if (usb_set_interface (s->usbdev, _DABUSB_IF, 1) < 0) {
                mutex_unlock(&s->mutex);
                dev_err(&s->usbdev->dev, "set_interface failed\n");
-               unlock_kernel();
                return -EINVAL;
        }
        s->opened = 1;
        file->private_data = s;
 
        r = nonseekable_open(inode, file);
-       unlock_kernel();
        return r;
 }
 
 
        dbg("dabusb_ioctl");
 
-       lock_kernel();
-       if (s->remove_pending) {
-               unlock_kernel();
+       if (s->remove_pending)
                return -EIO;
-       }
 
        mutex_lock(&s->mutex);
 
        if (!s->usbdev) {
                mutex_unlock(&s->mutex);
-               unlock_kernel();
                return -EIO;
        }
 
                break;
        }
        mutex_unlock(&s->mutex);
-       unlock_kernel();
        return ret;
 }