[patch 3/5] introduction of usb_anchor and overhaul of usb-skeleton

Hi,

this patch set introduces usb_anchor and uses it to implement all modern
APIs in the skeleton driver.

- support for suspend/resume

	Regards
		Oliver
Signed-off-by: Oliver Neukum <[email protected]>
-----

--- linux-2.6.22-rc2/drivers/usb/usb-skeleton.c.1	2007-05-25 12:52:17.000000000 +0200
+++ linux-2.6.22-rc2-autosuspend/drivers/usb/usb-skeleton.c	2007-05-25 13:05:01.000000000 +0200
@@ -60,6 +60,7 @@ struct usb_skel {
 	__u8			bulk_in_endpointAddr;	/* the address of the bulk in endpoint */
 	__u8			bulk_out_endpointAddr;	/* the address of the bulk out endpoint */
 	int			errors;			/* the last request tanked */
+	int			open_count;		/* count the number of openers */
 	spinlock_t		err_lock;		/* lock for errors */
 	struct kref		kref;
 	struct mutex		io_mutex;		/* synchronize I/O with disconnect */
@@ -106,18 +107,29 @@ static int skel_open(struct inode *inode
 
 	/* increment our usage count for the device */
 	kref_get(&dev->kref);
-	/* now we can drop the lock */
+
+	/* now we can drop the common lock */
+	mutex_lock(&dev->io_mutex);
 	mutex_unlock(&skel_open_lock);
 
-	/* prevent the device from being autosuspended */
-	retval = usb_autopm_get_interface(interface);
-	if (retval) {
+	if (!dev->open_count++) {
+		retval = usb_autopm_get_interface(interface);	
+			if (retval) {
+				mutex_unlock(&dev->io_mutex);
+				kref_put(&dev->kref, skel_delete);
+				goto exit;
+			}
+	} /* else { //uncomment this block if you want exclusive open
+		retval = -EBUSY;
+		dev->open_count--;
+		mutex_unlock(&dev->io_mutex);
 		kref_put(&dev->kref, skel_delete);
 		goto exit;
-	}
+	} */
 
 	/* save our object in the file's private structure */
 	file->private_data = dev;
+	mutex_unlock(&dev->io_mutex);
 
 exit:
 	return retval;
@@ -133,7 +145,7 @@ static int skel_release(struct inode *in
 
 	/* allow the device to be autosuspended */
 	mutex_lock(&dev->io_mutex);
-	if (dev->interface)
+	if (!--dev->open_count && dev->interface)
 		usb_autopm_put_interface(dev->interface);
 	mutex_unlock(&dev->io_mutex);
 
@@ -449,10 +461,27 @@ static void skel_draw_down(struct usb_sk
 		usb_kill_anchored_urbs(&dev->submitted);
 }
 
+static int skel_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct usb_skel *dev = usb_get_intfdata(intf);
+
+	if (!dev)
+		return 0;
+	skel_draw_down(dev);
+	return 0;
+}
+
+static int skel_resume (struct usb_interface *intf)
+{
+	return 0;
+}
+
 static struct usb_driver skel_driver = {
 	.name =		"skeleton",
 	.probe =	skel_probe,
 	.disconnect =	skel_disconnect,
+	.suspend =	skel_suspend,
+	.resume =	skel_resume,
 	.id_table =	skel_table,
 	.supports_autosuspend = 1,
 };

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel