e1000e: fix double release of mutex

commit 30bb0e0dce78427f3e5cb728d6b5ea73acbefffa upstream.

During a reset, releasing the swflag after it failed to be acquired would
cause a double unlock of the mutex.  Instead, test whether acquisition of
the swflag was successful and if not, do not release the swflag.  The reset
must still be done to bring the device to a quiescent state.

This resolves [BUG 12200] BUG: bad unlock balance detected! e1000e
http://bugzilla.kernel.org/show_bug.cgi?id=12200

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index bcd2bc477af29110636abec9920b3f4a76a244b7..79be7686c6cade5a382d0d8ab76cc932759d29b2 100644 (file)
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -1791,12 +1791,17 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
                ctrl |= E1000_CTRL_PHY_RST;
        }
        ret_val = e1000_acquire_swflag_ich8lan(hw);
+       /* Whether or not the swflag was acquired, we need to reset the part */
        hw_dbg(hw, "Issuing a global reset to ich8lan");
        ew32(CTRL, (ctrl | E1000_CTRL_RST));
        msleep(20);
 
-       /* release the swflag because it is not reset by hardware reset */
-       e1000_release_swflag_ich8lan(hw);
+       if (!ret_val) {
+               /* release the swflag because it is not reset by
+                * hardware reset
+                */
+               e1000_release_swflag_ich8lan(hw);
+       }
 
        ret_val = e1000e_get_auto_rd_done(hw);
        if (ret_val) {