From: Denis Joseph Barrow <D.Barrow@option.com>
Date: Thu, 15 Jan 2009 13:31:24 +0000 (+0000)
Subject: tty: Fix double grabbing of a spinlock
X-Git-Tag: v2.6.29-rc2~69
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=d45eb81c3e345fabaf27ef3ab437b85c0bf9fafa;p=linux-2.6-omap-h63xx.git

tty: Fix double grabbing of a spinlock

The HSO changes for kref introduced a recursive spinlock take. All
functions which call put_rxbuf_data already have serial->serial_lock
grabbed.

[Comment to code added-AC]

Signed-off-by: Denis Joseph Barrow <D.Barrow@option.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 9df04dd1332..e25a58f6ff6 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2044,9 +2044,8 @@ static int put_rxbuf_data(struct urb *urb, struct hso_serial *serial)
 		return -2;
 	}
 
-	spin_lock(&serial->serial_lock);
+	/* All callers to put_rxbuf_data hold serial_lock */
 	tty = tty_kref_get(serial->tty);
-	spin_unlock(&serial->serial_lock);
 
 	/* Push data to tty */
 	if (tty) {