X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fusb%2Fcore%2Ffile.c;h=8133c99c6c5caf7cb1f384c71360f15e6c4fbf54;hb=b8a0b6ccf2ba2519ace65d782b41ee91bf3c3778;hp=01c857ac27afc09eed98c1a190d794073b73c470;hpb=fe6af6faec078ec8137631f24cb541f9918244f0;p=linux-2.6-omap-h63xx.git

diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 01c857ac27a..8133c99c6c5 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -16,15 +16,15 @@
  */
 
 #include <linux/module.h>
-#include <linux/spinlock.h>
 #include <linux/errno.h>
+#include <linux/rwsem.h>
 #include <linux/usb.h>
 
 #include "usb.h"
 
 #define MAX_USB_MINORS	256
 static const struct file_operations *usb_minors[MAX_USB_MINORS];
-static DEFINE_SPINLOCK(minor_lock);
+static DECLARE_RWSEM(minor_rwsem);
 
 static int usb_open(struct inode * inode, struct file * file)
 {
@@ -33,14 +33,11 @@ static int usb_open(struct inode * inode, struct file * file)
 	int err = -ENODEV;
 	const struct file_operations *old_fops, *new_fops = NULL;
 
-	spin_lock (&minor_lock);
+	down_read(&minor_rwsem);
 	c = usb_minors[minor];
 
-	if (!c || !(new_fops = fops_get(c))) {
-		spin_unlock(&minor_lock);
-		return err;
-	}
-	spin_unlock(&minor_lock);
+	if (!c || !(new_fops = fops_get(c)))
+		goto done;
 
 	old_fops = file->f_op;
 	file->f_op = new_fops;
@@ -52,6 +49,8 @@ static int usb_open(struct inode * inode, struct file * file)
 		file->f_op = fops_get(old_fops);
 	}
 	fops_put(old_fops);
+ done:
+	up_read(&minor_rwsem);
 	return err;
 }
 
@@ -166,7 +165,7 @@ int usb_register_dev(struct usb_interface *intf,
 	if (class_driver->fops == NULL)
 		goto exit;
 
-	spin_lock (&minor_lock);
+	down_write(&minor_rwsem);
 	for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
 		if (usb_minors[minor])
 			continue;
@@ -176,7 +175,7 @@ int usb_register_dev(struct usb_interface *intf,
 		retval = 0;
 		break;
 	}
-	spin_unlock (&minor_lock);
+	up_write(&minor_rwsem);
 
 	if (retval)
 		goto exit;
@@ -197,15 +196,15 @@ int usb_register_dev(struct usb_interface *intf,
 	intf->usb_dev = device_create(usb_class->class, &intf->dev,
 				      MKDEV(USB_MAJOR, minor), "%s", temp);
 	if (IS_ERR(intf->usb_dev)) {
-		spin_lock (&minor_lock);
+		down_write(&minor_rwsem);
 		usb_minors[intf->minor] = NULL;
-		spin_unlock (&minor_lock);
+		up_write(&minor_rwsem);
 		retval = PTR_ERR(intf->usb_dev);
 	}
 exit:
 	return retval;
 }
-EXPORT_SYMBOL(usb_register_dev);
+EXPORT_SYMBOL_GPL(usb_register_dev);
 
 /**
  * usb_deregister_dev - deregister a USB device's dynamic minor.
@@ -236,9 +235,9 @@ void usb_deregister_dev(struct usb_interface *intf,
 
 	dbg ("removing %d minor", intf->minor);
 
-	spin_lock (&minor_lock);
+	down_write(&minor_rwsem);
 	usb_minors[intf->minor] = NULL;
-	spin_unlock (&minor_lock);
+	up_write(&minor_rwsem);
 
 	snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
 	device_destroy(usb_class->class, MKDEV(USB_MAJOR, intf->minor));
@@ -246,6 +245,4 @@ void usb_deregister_dev(struct usb_interface *intf,
 	intf->minor = -1;
 	destroy_usb_class();
 }
-EXPORT_SYMBOL(usb_deregister_dev);
-
-
+EXPORT_SYMBOL_GPL(usb_deregister_dev);