From: Jose Abreu Jose.Abreu@synopsys.com
[ Upstream commit eaf4fac478077d4ed57cbca2c044c4b58a96bd98 ]
The maximum MTU value is determined by the maximum size of TX FIFO so that a full packet can fit in the FIFO. Add a check for this in the MTU change callback.
Also check if provided and rounded MTU does not passes the maximum limit of 16K.
Changes from v2: - Align MTU before checking if its valid
Fixes: 7ac6653a085b ("stmmac: Move the STMicroelectronics driver") Signed-off-by: Jose Abreu Jose.Abreu@synopsys.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 014fe93..ec37ef7 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3604,12 +3604,24 @@ static void stmmac_set_rx_mode(struct net_device *dev) 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; + + if (txfifosz == 0) + txfifosz = priv->dma_cap.tx_fifo_size; + + txfifosz /= priv->plat->tx_queues_to_use;
if (netif_running(dev)) { netdev_err(priv->dev, "must be stopped to change its MTU\n"); return -EBUSY; }
+ new_mtu = STMMAC_ALIGN(new_mtu); + + /* If condition true, FIFO is too small or MTU too large */ + if ((txfifosz < new_mtu) || (new_mtu > BUF_SIZE_16KiB)) + return -EINVAL; + dev->mtu = new_mtu;
netdev_update_features(dev);