From f24dfbcaff341875735461e7e63d4f7b64409f8b Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Fri, 16 May 2008 13:53:00 -0600
Subject: [PATCH] --- yaml --- r: 100305 b: refs/heads/master c:
 b8c71d7ae2a7f723d171d9175212b6d0a727655d h: refs/heads/master i:   100303:
 86a848d50f2528da86a821672f027e7390e61ca5 v: v3

---
 [refs]                     |  2 +-
 trunk/drivers/char/tlclk.c | 19 ++++++++++++-------
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index f9f97cec3e78..5bb44c225773 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f4943db14f5071ecbf7ca76722e59a2fd22bda4d
+refs/heads/master: b8c71d7ae2a7f723d171d9175212b6d0a727655d
diff --git a/trunk/drivers/char/tlclk.c b/trunk/drivers/char/tlclk.c
index 35e58030d296..8f2284be68e1 100644
--- a/trunk/drivers/char/tlclk.c
+++ b/trunk/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)