X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fusb%2Fmisc%2Fusblcd.c;h=20777d01db62c4fdd705cde8307d5117e79c24e5;hb=564d61d30effcc727f9519538143a6c6aeb92e46;hp=719842032712b68c0e42c22b16c58d57332a65a7;hpb=532df780a2012ad75b3f078647f229c4dabd99d1;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c
index 71984203271..20777d01db6 100644
--- a/drivers/usb/misc/usblcd.c
+++ b/drivers/usb/misc/usblcd.c
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
+#include <linux/mutex.h>
 #include <asm/uaccess.h>
 #include <linux/usb.h>
 
@@ -34,6 +35,8 @@ static struct usb_device_id id_table [] = {
 };
 MODULE_DEVICE_TABLE (usb, id_table);
 
+static DEFINE_MUTEX(open_disc_mutex);
+
 
 struct usb_lcd {
 	struct usb_device *	udev;			/* init: probe_lcd */
@@ -79,12 +82,16 @@ static int lcd_open(struct inode *inode, struct file *file)
 		return -ENODEV;
 	}
 
+	mutex_lock(&open_disc_mutex);
 	dev = usb_get_intfdata(interface);
-	if (!dev)
+	if (!dev) {
+		mutex_unlock(&open_disc_mutex);
 		return -ENODEV;
+	}
 
 	/* increment our usage count for the device */
 	kref_get(&dev->kref);
+	mutex_unlock(&open_disc_mutex);
 
 	/* grab a power reference */
 	r = usb_autopm_get_interface(interface);
@@ -393,8 +400,10 @@ static void lcd_disconnect(struct usb_interface *interface)
 	struct usb_lcd *dev;
         int minor = interface->minor;
 
+	mutex_lock(&open_disc_mutex);
         dev = usb_get_intfdata(interface);
         usb_set_intfdata(interface, NULL);
+	mutex_unlock(&open_disc_mutex);
 
         /* give back our minor */
         usb_deregister_dev(interface, &lcd_class);