[PATCH net-next 3/3] net: xgene: avoid bogus maybe-uninitialized warning

[Arnd Bergmann]

In some configurations, gcc cannot trace the state of variables
across a spin_unlock() barrier, leading to a warning about
correct code:

xgene_enet_main.c: In function 'xgene_enet_start_xmit':
../../../phy/mdio-xgene.h:112:14: error: 'mss_index' may be used uninitialized 
in this function [-Werror=maybe-uninitialized]

Here we can trivially move the assignment before that spin_unlock,
which reliably avoids the warning.

Fixes: e3978673f514 ("drivers: net: xgene: Fix MSS programming")
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c 
b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
index 6c7eea8b36af..dba4b883e9a3 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
@@ -319,11 +319,11 @@ static int xgene_enet_setup_mss(struct net_device *ndev, 
u32 mss)
                }
        }
 
-       spin_unlock(&pdata->mss_lock);
-
        /* No slots with ref_count = 0 available, return busy */
        if (!mss_index_found)
-               return -EBUSY;
+               mss_index = -EBUSY;
+
+       spin_unlock(&pdata->mss_lock);
 
        return mss_index;
 }
-- 
2.9.0