[PATCH 7/8] tty: Fix double grabbing of a spinlock

[Alan Cox]

From: Denis Joseph Barrow <D.Barrow@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Alan Cox <alan@xxxxxxxxxx>
---

 drivers/net/usb/hso.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)


diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 9df04dd..e25a58f 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) {

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