From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Igor Pecovnik <igor.pecovnik@gmail.com>
Date: Wed, 21 Jul 2021 20:59:39 +0000
Subject: Disable MTU validation

This patch reverts: https://github.com/torvalds/linux/commit/eaf4fac478077d4ed57cbca2c044c4b58a96bd98

It works around following issues:
 - no way to change MTU (tx_fifo_size is reported as 0 for Rockchip's dwmac)

Signed-off-by: Piotr Szczepanik <piter75@gmail.com>
Signed-off-by: Igor Pecovnik <igor.pecovnik@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 ----------
 1 file changed, 12 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 111111111111..222222222222 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5878,27 +5878,15 @@ 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;
 	struct stmmac_dma_conf *dma_conf;
 	const int mtu = new_mtu;
 	int ret;
 
-	if (txfifosz == 0)
-		txfifosz = priv->dma_cap.tx_fifo_size;
-
-	txfifosz /= priv->plat->tx_queues_to_use;
-
 	if (stmmac_xdp_is_enabled(priv) && new_mtu > ETH_DATA_LEN) {
 		netdev_dbg(priv->dev, "Jumbo frames not supported for XDP\n");
 		return -EINVAL;
 	}
 
-	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;
-
 	if (netif_running(dev)) {
 		netdev_dbg(priv->dev, "restarting interface to change its MTU\n");
 		/* Try to allocate the new DMA conf with the new mtu */
-- 
Armbian

