From 25719e6b4631959c9ecb1db6967537a124c4a7fa Mon Sep 17 00:00:00 2001
From: Stefani Seibold <stefani@seibold.net>
Date: Tue, 5 Jan 2010 14:30:31 +0100
Subject: USB: serial: fix USB serial fix kfifo_len locking

This patch fix a possible race bug in drivers/usb/serial/generic with
the new kfifo API.

Please apply it to the 2.6.33-rc* tree.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/usb/serial/generic.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

(limited to 'drivers/usb/serial/generic.c')

diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index f1ea3a33b6e6..5ce033ab9b99 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -386,12 +386,12 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
 
 	dbg("%s - port %d", __func__, port->number);
 
-	if (serial->type->max_in_flight_urbs) {
-		spin_lock_irqsave(&port->lock, flags);
+	spin_lock_irqsave(&port->lock, flags);
+	if (serial->type->max_in_flight_urbs)
 		chars = port->tx_bytes_flight;
-		spin_unlock_irqrestore(&port->lock, flags);
-	} else if (serial->num_bulk_out)
+	else if (serial->num_bulk_out)
 		chars = kfifo_len(&port->write_fifo);
+	spin_unlock_irqrestore(&port->lock, flags);
 
 	dbg("%s - returns %d", __func__, chars);
 	return chars;
-- 
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