USB: legousbtower: make poll notice disconnect
poll needs to return an error if a device is disconnected
- make poll check for device's presence
- wake all waiters in disconnect
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 97efeae..faa6d62 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -552,6 +552,9 @@
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 @@
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);
}