X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fusb%2Fcore%2Ffile.c;h=f794f07cfb3330f92ebfb135f1f0b8e601613594;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=37b13368c8145c9ca8522aab5d074d30dc3eb42f;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 37b13368c..f794f07cf 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -1,5 +1,5 @@
 /*
- * drivers/usb/file.c
+ * drivers/usb/core/file.c
  *
  * (C) Copyright Linus Torvalds 1999
  * (C) Copyright Johannes Erdfelt 1999-2001
@@ -15,7 +15,6 @@
  *
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/errno.h>
@@ -24,15 +23,15 @@
 #include "usb.h"
 
 #define MAX_USB_MINORS	256
-static struct file_operations *usb_minors[MAX_USB_MINORS];
+static const struct file_operations *usb_minors[MAX_USB_MINORS];
 static DEFINE_SPINLOCK(minor_lock);
 
 static int usb_open(struct inode * inode, struct file * file)
 {
 	int minor = iminor(inode);
-	struct file_operations *c;
+	const struct file_operations *c;
 	int err = -ENODEV;
-	struct file_operations *old_fops, *new_fops = NULL;
+	const struct file_operations *old_fops, *new_fops = NULL;
 
 	spin_lock (&minor_lock);
 	c = usb_minors[minor];
@@ -56,38 +55,71 @@ static int usb_open(struct inode * inode, struct file * file)
 	return err;
 }
 
-static struct file_operations usb_fops = {
+static const struct file_operations usb_fops = {
 	.owner =	THIS_MODULE,
 	.open =		usb_open,
 };
 
-static struct class *usb_class;
+static struct usb_class {
+	struct kref kref;
+	struct class *class;
+} *usb_class;
 
-int usb_major_init(void)
+static int init_usb_class(void)
 {
-	int error;
+	int result = 0;
 
-	error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
-	if (error) {
-		err("unable to get major %d for usb devices", USB_MAJOR);
-		goto out;
+	if (usb_class != NULL) {
+		kref_get(&usb_class->kref);
+		goto exit;
+	}
+
+	usb_class = kmalloc(sizeof(*usb_class), GFP_KERNEL);
+	if (!usb_class) {
+		result = -ENOMEM;
+		goto exit;
 	}
 
-	usb_class = class_create(THIS_MODULE, "usb");
-	if (IS_ERR(usb_class)) {
-		error = PTR_ERR(usb_class);
+	kref_init(&usb_class->kref);
+	usb_class->class = class_create(THIS_MODULE, "usb");
+	if (IS_ERR(usb_class->class)) {
+		result = IS_ERR(usb_class->class);
 		err("class_create failed for usb devices");
-		unregister_chrdev(USB_MAJOR, "usb");
-		goto out;
+		kfree(usb_class);
+		usb_class = NULL;
 	}
 
-out:
+exit:
+	return result;
+}
+
+static void release_usb_class(struct kref *kref)
+{
+	/* Ok, we cheat as we know we only have one usb_class */
+	class_destroy(usb_class->class);
+	kfree(usb_class);
+	usb_class = NULL;
+}
+
+static void destroy_usb_class(void)
+{
+	if (usb_class)
+		kref_put(&usb_class->kref, release_usb_class);
+}
+
+int usb_major_init(void)
+{
+	int error;
+
+	error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
+	if (error)
+		err("unable to get major %d for usb devices", USB_MAJOR);
+
 	return error;
 }
 
 void usb_major_cleanup(void)
 {
-	class_destroy(usb_class);
 	unregister_chrdev(USB_MAJOR, "usb");
 }
 
@@ -146,6 +178,10 @@ int usb_register_dev(struct usb_interface *intf,
 	}
 	spin_unlock (&minor_lock);
 
+	if (retval)
+		goto exit;
+
+	retval = init_usb_class();
 	if (retval)
 		goto exit;
 
@@ -158,7 +194,7 @@ int usb_register_dev(struct usb_interface *intf,
 		++temp;
 	else
 		temp = name;
-	intf->class_dev = class_device_create(usb_class, NULL,
+	intf->class_dev = class_device_create(usb_class->class, NULL,
 					      MKDEV(USB_MAJOR, minor),
 					      &intf->dev, "%s", temp);
 	if (IS_ERR(intf->class_dev)) {
@@ -206,9 +242,10 @@ void usb_deregister_dev(struct usb_interface *intf,
 	spin_unlock (&minor_lock);
 
 	snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
-	class_device_destroy(usb_class, MKDEV(USB_MAJOR, intf->minor));
+	class_device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
 	intf->class_dev = NULL;
 	intf->minor = -1;
+	destroy_usb_class();
 }
 EXPORT_SYMBOL(usb_deregister_dev);