From 91c19dff0b9800ce87774510b953e2d3ebac3424 Mon Sep 17 00:00:00 2001 From: David Wu Date: Wed, 13 Jan 2021 11:41:09 +0800 Subject: [PATCH] net: stmmac: Fixed mtu channged by cache aligned BugLink: https://bugs.launchpad.net/bugs/1915186 [ Upstream commit 5b55299eed78538cc4746e50ee97103a1643249c ] Since the original mtu is not used when the mtu is updated, the mtu is aligned with cache, this will get an incorrect. For example, if you want to configure the mtu to be 1500, but mtu 1536 is configured in fact. Fixed: eaf4fac478077 ("net: stmmac: Do not accept invalid MTU values") Signed-off-by: David Wu Link: https://lore.kernel.org/r/20210113034109.27865-1-david.wu@rock-chips.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: William Breathitt Gray --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 18c5a9bb6759..ce5d3e9e5dff 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3739,6 +3739,7 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu) { struct stmmac_priv *priv = netdev_priv(dev); int txfifosz = priv->plat->tx_fifo_size; + const int mtu = new_mtu; if (txfifosz == 0) txfifosz = priv->dma_cap.tx_fifo_size; @@ -3756,7 +3757,7 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu) if ((txfifosz < new_mtu) || (new_mtu > BUF_SIZE_16KiB)) return -EINVAL; - dev->mtu = new_mtu; + dev->mtu = mtu; netdev_update_features(dev); -- 2.39.5