net: stmmac: fix maxmtu assignment to be within valid range

[karo-tx-linux.git] / drivers / net / ethernet / stmicro / stmmac / stmmac_main.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 39eb7a65bb9f6a6137ffe13c4c2e776720311db1..a276a32d57f24374444ec06c02b3707fec8fae0a 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3319,8 +3319,16 @@ int stmmac_dvr_probe(struct device *device,
                ndev->max_mtu = JUMBO_LEN;
        else
                ndev->max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);
-       if (priv->plat->maxmtu < ndev->max_mtu)
+       /* Will not overwrite ndev->max_mtu if plat->maxmtu > ndev->max_mtu
+        * as well as plat->maxmtu < ndev->min_mtu which is a invalid range.
+        */
+       if ((priv->plat->maxmtu < ndev->max_mtu) &&
+           (priv->plat->maxmtu >= ndev->min_mtu))
                ndev->max_mtu = priv->plat->maxmtu;
+       else if (priv->plat->maxmtu < ndev->min_mtu)
+               netdev_warn(priv->dev,
+                           "%s: warning: maxmtu having invalid value (%d)\n",
+                           __func__, priv->plat->maxmtu);
 
        if (flow_ctrl)
                priv->flow_ctrl = FLOW_AUTO;    /* RX/TX pause on */