serial: drivers/serial/pmac_zilog.c: add missing unlock

In an error handling case the lock is not unlocked.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irqsave (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/serial/pmac_zilog.c b/drivers/serial/pmac_zilog.c
index 4eaa043ca2a8..700e10833bf9 100644
--- a/drivers/serial/pmac_zilog.c
+++ b/drivers/serial/pmac_zilog.c
@@ -752,8 +752,10 @@ static void pmz_break_ctl(struct uart_port *port, int break_state)
                 uap->curregs[R5] = new_reg;
 
                 /* NOTE: Not subject to 'transmitter active' rule. */
-                if (ZS_IS_ASLEEP(uap))
+                if (ZS_IS_ASLEEP(uap)) {
+                        spin_unlock_irqrestore(&port->lock, flags);
                         return;
+                }
                 write_zsreg(uap, R5, uap->curregs[R5]);
         }