Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (142 commits)
  USB: Fix sysfs paths in documentation
  USB: skeleton: fix coding style issues.
  USB: O_NONBLOCK in read path of skeleton
  USB: make usb-skeleton honor O_NONBLOCK in write path
  USB: skel_read really sucks royally
  USB: Add hub descriptor update hook for xHCI
  USB: xhci: Support USB hubs.
  USB: xhci: Set multi-TT field for LS/FS devices under hubs.
  USB: xhci: Set route string for all devices.
  USB: xhci: Fix command wait list handling.
  USB: xhci: Change how xHCI commands are handled.
  USB: xhci: Refactor input device context setup.
  USB: xhci: Endpoint representation refactoring.
  USB: gadget: ether needs to select CRC32
  USB: fix USBTMC get_capabilities success handling
  USB: fix missing error check in probing
  USB: usbfs: add USBDEVFS_URB_BULK_CONTINUATION flag
  USB: support for autosuspend in sierra while online
  USB: ehci-dbgp,ehci: Allow dbpg to work with suspend/resume
  USB: ehci-dbgp,documentation: Documentation updates for ehci-dbgp
  ...

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 97efeaec4d52..faa6d623de78 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -552,6 +552,9 @@ static unsigned int tower_poll (struct file *file, poll_table *wait)
 
         dev = file->private_data;
 
+        if (!dev->udev)
+                return POLLERR | POLLHUP;
+
         poll_wait(file, &dev->read_wait, wait);
         poll_wait(file, &dev->write_wait, wait);
 
@@ -1025,6 +1028,9 @@ static void tower_disconnect (struct usb_interface *interface)
                 tower_delete (dev);
         } else {
                 dev->udev = NULL;
+                /* wake up pollers */
+                wake_up_interruptible_all(&dev->read_wait);
+                wake_up_interruptible_all(&dev->write_wait);
                 mutex_unlock(&dev->lock);
         }