[PATCH] USB: Fix disconnect bug in dummy_hcd

Greg:

This patch fixes a bug in disconnect handling for the dummy_hcd driver.
After a disconnect the driver would still accept URBs for endpoint 0,
leading to an oops.  It also improves the ad-hoc technique used by the
driver to track its gadget's struct usb_device and fixes the way
port-power changes are handled.  Please apply.

Alan Stern
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/gadget/dummy_hcd.c

@@ -825,8 +825,7 @@ static int dummy_urb_enqueue (
 	dum = container_of (hcd, struct dummy, hcd);
 	spin_lock_irqsave (&dum->lock, flags);
 
-	if (!dum->hdev)
-		dum->hdev = urb->dev->hcpriv;
+	dum->hdev = urb->dev->hcpriv;
 	urb->hcpriv = dum;
 	if (usb_pipetype (urb->pipe) == PIPE_CONTROL)
 		urb->error_count = 1;		/* mark as a new urb */
@@ -994,10 +993,17 @@ static int periodic_bytes (struct dummy *dum, struct dummy_ep *ep)
 	return limit;
 }
 
+#define is_active(dum)	((dum->port_status & \
+		(USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE | \
+			USB_PORT_STAT_SUSPEND)) \
+		== (USB_PORT_STAT_CONNECTION | USB_PORT_STAT_ENABLE))
+
 static struct dummy_ep *find_endpoint (struct dummy *dum, u8 address)
 {
 	int		i;
 
+	if (!is_active (dum))
+		return NULL;
 	if ((address & ~USB_DIR_IN) == 0)
 		return &dum->ep [0];
 	for (i = 1; i < DUMMY_ENDPOINTS; i++) {
@@ -1011,6 +1017,8 @@ static struct dummy_ep *find_endpoint (struct dummy *dum, u8 address)
 	return NULL;
 }
 
+#undef is_active
+
 #define Dev_Request	(USB_TYPE_STANDARD | USB_RECIP_DEVICE)
 #define Dev_InRequest	(Dev_Request | USB_DIR_IN)
 #define Intf_Request	(USB_TYPE_STANDARD | USB_RECIP_INTERFACE)
@@ -1404,9 +1412,8 @@ static int dummy_hub_control (
 			break;
 		case USB_PORT_FEAT_POWER:
 			dum->port_status = 0;
-			dum->address = 0;
-			dum->hdev = 0;
 			dum->resuming = 0;
+			stop_activity(dum, dum->driver);
 			break;
 		default:
 			dum->port_status &= ~(1 << wValue);