[ldv-project] [PATCH] e1000e: fix mismatch in mutex lock-unlock in e1000_reset_hw_82571()

[Alexey Khoroshilov]

If e1000_get_hw_semaphore_82574() succeed, it acquires swflag_mutex,
otherwise it does not. But the returned value of
e1000_get_hw_semaphore_82574() is ignored, so unlocking of swflag_mutex
happens anyway.

The patch fixes the issue by breaking reset if MIC ownership is not acquired.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov at ispras.ru>
---
 drivers/net/ethernet/intel/e1000e/82571.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000e/82571.c b/drivers/net/ethernet/intel/e1000e/82571.c
index 2faffbd..a6bd80e 100644
--- a/drivers/net/ethernet/intel/e1000e/82571.c
+++ b/drivers/net/ethernet/intel/e1000e/82571.c
@@ -1003,8 +1003,10 @@ static s32 e1000_reset_hw_82571(struct e1000_hw *hw)
 	default:
 		break;
 	}
-	if (ret_val)
+	if (ret_val) {
 		e_dbg("Cannot acquire MDIO ownership\n");
+		return ret_val;
+	}
 
 	ctrl = er32(CTRL);
 
-- 
1.7.9.5