tlckl: BKL pushdown

Put explicit lock_kernel calls into tlclk_open()

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/drivers/char/tlclk.c b/drivers/char/tlclk.c
index 35e5803..8f2284b 100644 (file)
--- a/drivers/char/tlclk.c
+++ b/drivers/char/tlclk.c
@@ -36,6 +36,7 @@
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
+#include <linux/smp_lock.h>
 #include <linux/timer.h>
 #include <linux/sysfs.h>
 #include <linux/device.h>
@@ -204,11 +205,14 @@ static int tlclk_open(struct inode *inode, struct file *filp)
 {
        int result;
 
-       if (test_and_set_bit(0, &useflags))
-               return -EBUSY;
+       lock_kernel();
+       if (test_and_set_bit(0, &useflags)) {
+               result = -EBUSY;
                /* this legacy device is always one per system and it doesn't
                 * know how to handle multiple concurrent clients.
                 */
+               goto out;
+       }
 
        /* Make sure there is no interrupt pending while
         * initialising interrupt handler */
@@ -218,13 +222,14 @@ static int tlclk_open(struct inode *inode, struct file *filp)
         * we can't share this IRQ */
        result = request_irq(telclk_interrupt, &tlclk_interrupt,
                             IRQF_DISABLED, "telco_clock", tlclk_interrupt);
-       if (result == -EBUSY) {
+       if (result == -EBUSY)
                printk(KERN_ERR "tlclk: Interrupt can't be reserved.\n");
-               return -EBUSY;
-       }
-       inb(TLCLK_REG6);        /* Clear interrupt events */
+       else
+               inb(TLCLK_REG6);        /* Clear interrupt events */
 
-       return 0;
+out:
+       unlock_kernel();
+       return result;
 }
 
 static int tlclk_release(struct inode *inode, struct file *filp)