1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/char/pcmcia/cm4040_cs.c b/drivers/char/pcmcia/cm4040_cs.c
index 035084c07329..6181f8a9b0bd 100644
--- a/drivers/char/pcmcia/cm4040_cs.c
+++ b/drivers/char/pcmcia/cm4040_cs.c
@@ -26,6 +26,7 @@
 #include <linux/fs.h>
 #include <linux/delay.h>
 #include <linux/poll.h>
+#include <linux/smp_lock.h>
 #include <linux/wait.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
@@ -448,23 +449,30 @@ static int cm4040_open(struct inode *inode, struct file *filp)
         struct reader_dev *dev;
         struct pcmcia_device *link;
         int minor = iminor(inode);
+        int ret;
 
         if (minor >= CM_MAX_DEV)
                 return -ENODEV;
 
+        lock_kernel();
         link = dev_table[minor];
-        if (link == NULL || !pcmcia_dev_present(link))
-                return -ENODEV;
+        if (link == NULL || !pcmcia_dev_present(link)) {
+                ret = -ENODEV;
+                goto out;
+        }
 
-        if (link->open)
-                return -EBUSY;
+        if (link->open) {
+                ret = -EBUSY;
+                goto out;
+        }
 
         dev = link->priv;
         filp->private_data = dev;
 
         if (filp->f_flags & O_NONBLOCK) {
                 DEBUGP(4, dev, "filep->f_flags O_NONBLOCK set\n");
-                return -EAGAIN;
+                ret = -EAGAIN;
+                goto out;
         }
 
         link->open = 1;
@@ -473,7 +481,10 @@ static int cm4040_open(struct inode *inode, struct file *filp)
         mod_timer(&dev->poll_timer, jiffies + POLL_PERIOD);
 
         DEBUGP(2, dev, "<- cm4040_open (successfully)\n");
-        return nonseekable_open(inode, filp);
+        ret = nonseekable_open(inode, filp);
+out:
+        unlock_kernel();
+        return ret;
 }
 
 static int cm4040_close(struct inode *inode, struct file *filp)