drivers/isdn/hardware/mISDN: Add missing spin_unlock

Add a spin_unlock missing on the error path.  The return value of write_reg
seems to be completely ignored, so it seems that the lock should be
released in every case.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E1;
@@

* spin_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* spin_unlock(E1,...);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index b3b7e2879bac..8700474747e8 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -97,8 +97,10 @@ static int write_reg(struct hfcsusb *hw, __u8 reg, __u8 val)
                         hw->name, __func__, reg, val);
 
         spin_lock(&hw->ctrl_lock);
-        if (hw->ctrl_cnt >= HFC_CTRL_BUFSIZE)
+        if (hw->ctrl_cnt >= HFC_CTRL_BUFSIZE) {
+                spin_unlock(&hw->ctrl_lock);
                 return 1;
+        }
         buf = &hw->ctrl_buff[hw->ctrl_in_idx];
         buf->hfcs_reg = reg;
         buf->reg_val = val;