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Commit 7bbe990c authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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USB: autosuspend for usblcd 



this patch implements autosuspend for the usblcd driver. It uses
the new usb_anchor infrastructure. Many thanks to Georges for testing.

Signed-off-by: default avatarOliver Neukum <oneukum@suse.de>
Cc: Georges Toth <g.toth@e-biz.lu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 55b3fd41

drivers/usb/misc/usblcd.c

+43 −3
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ struct usb_lcd { 
	struct kref		kref;

	struct semaphore	limit_sem;		/* to stop writes at full throttle from

							 * using up all RAM */

	struct usb_anchor	submitted;		/* URBs to wait for before suspend */

};

#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
@@ -67,7 +68,7 @@ static int lcd_open(struct inode *inode, struct file *file) 
{

	struct usb_lcd *dev;

	struct usb_interface *interface;

	int subminor;

	int subminor, r;



	subminor = iminor(inode);
@@ -85,6 +86,13 @@ static int lcd_open(struct inode *inode, struct file *file) 
	/* increment our usage count for the device */

	kref_get(&dev->kref);



	/* grab a power reference */

	r = usb_autopm_get_interface(interface);

	if (r < 0) {

		kref_put(&dev->kref, lcd_delete);

		return r;

	}



	/* save our object in the file's private structure */

	file->private_data = dev;
@@ -100,6 +108,7 @@ static int lcd_release(struct inode *inode, struct file *file) 
		return -ENODEV;



	/* decrement the count on our device */

	usb_autopm_put_interface(dev->interface);

	kref_put(&dev->kref, lcd_delete);

	return 0;

}
@@ -226,11 +235,13 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, siz 
			  buf, count, lcd_write_bulk_callback, dev);

	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;



	usb_anchor_urb(urb, &dev->submitted);

	

	/* send the data out the bulk port */

	retval = usb_submit_urb(urb, GFP_KERNEL);

	if (retval) {

		err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval);

		goto error;

		goto error_unanchor;

	}

	

	/* release our reference to this urb, the USB core will eventually free it entirely */
@@ -238,7 +249,8 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, siz 


exit:

	return count;



error_unanchor:

	usb_unanchor_urb(urb);

error:

	usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);

	usb_free_urb(urb);
@@ -283,6 +295,7 @@ static int lcd_probe(struct usb_interface *interface, const struct usb_device_id 
	}

	kref_init(&dev->kref);

	sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);

	init_usb_anchor(&dev->submitted);



	dev->udev = usb_get_dev(interface_to_usbdev(interface));

	dev->interface = interface;
@@ -350,6 +363,30 @@ static int lcd_probe(struct usb_interface *interface, const struct usb_device_id 
	return retval;

}



static void lcd_draw_down(struct usb_lcd *dev)

{

	int time;



	time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);

	if (!time)

		usb_kill_anchored_urbs(&dev->submitted);

}



static int lcd_suspend(struct usb_interface *intf, pm_message_t message)

{

	struct usb_lcd *dev = usb_get_intfdata(intf);



	if (!dev)

		return 0;

	lcd_draw_down(dev);

	return 0;

}



static int lcd_resume (struct usb_interface *intf)

{

	return 0;

}



static void lcd_disconnect(struct usb_interface *interface)

{

	struct usb_lcd *dev;
@@ -371,7 +408,10 @@ static struct usb_driver lcd_driver = { 
	.name =		"usblcd",

	.probe =	lcd_probe,

	.disconnect =	lcd_disconnect,

	.suspend =	lcd_suspend,

	.resume =	lcd_resume,

	.id_table =	id_table,

	.supports_autosuspend = 1,

};



static int __init usb_lcd_init(void)