[S390] monwriter: remove lock_kernel() from open() function

The lock_kernel() calls in the open() function are unnecessary because
misc_register() is called last in module_init() and concurrent open()
calls are handled by other means.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/s390/char/monwriter.c b/drivers/s390/char/monwriter.c
index 66fb8eba93f4..6532ed8b4afa 100644
--- a/drivers/s390/char/monwriter.c
+++ b/drivers/s390/char/monwriter.c
@@ -13,7 +13,6 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/errno.h>
-#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
@@ -185,13 +184,11 @@ static int monwrite_open(struct inode *inode, struct file *filp)
         monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
         if (!monpriv)
                 return -ENOMEM;
-        lock_kernel();
         INIT_LIST_HEAD(&monpriv->list);
         monpriv->hdr_to_read = sizeof(monpriv->hdr);
         mutex_init(&monpriv->thread_mutex);
         filp->private_data = monpriv;
         list_add_tail(&monpriv->priv_list, &mon_priv_list);
-        unlock_kernel();
         return nonseekable_open(inode, filp);
 }
 
@@ -364,6 +361,10 @@ static int __init mon_init(void)
                 goto out_driver;
         }
 
+        /*
+         * misc_register() has to be the last action in module_init(), because
+         * file operations will be available right after this.
+         */
         rc = misc_register(&mon_dev);
         if (rc)
                 goto out_device;