fix #1343: add MTU patches for intel drivers

ported from upstream / in-tree commits
91c527a55664ddf4bee26673a35f91748dae4142
and
45693bcb00cbd379c373ab22ccd9a9d4755cc7ed

Makefile

@@ -293,6 +293,7 @@ e1000e.ko e1000e: .compile_mark ${E1000ESRC}
 #	[ ! -e /lib/modules/${KVNAME}/build ] || rm /lib/modules/${KVNAME}/build
 	cd ${E1000EDIR}; patch -p1 < ../intel-module-gcc6-compat.patch
 	cd ${E1000EDIR}; patch -p1 < ../e1000e_4.10_compat.patch
+	cd ${E1000EDIR}; patch -p1 < ../e1000e_4.10_max-mtu.patch
 	cd ${E1000EDIR}/src; make BUILD_KERNEL=${KVNAME} KSRC=${TOP}/${KERNEL_SRC}
 	cp ${E1000EDIR}/src/e1000e.ko e1000e.ko
 
@@ -303,6 +304,7 @@ igb.ko igb: .compile_mark ${IGBSRC}
 	cd ${IGBDIR}; patch -p1 < ../intel-module-gcc6-compat.patch
 	cd ${IGBDIR}; patch -p1 < ../igb_4.9_compat.patch
 	cd ${IGBDIR}; patch -p1 < ../igb_4.10_compat.patch
+	cd ${IGBDIR}; patch -p1 < ../igb_4.10_max-mtu.patch
 	cd ${IGBDIR}/src; make BUILD_KERNEL=${KVNAME} KSRC=${TOP}/${KERNEL_SRC}
 	cp ${IGBDIR}/src/igb.ko igb.ko
 
@@ -311,6 +313,7 @@ ixgbe.ko ixgbe: .compile_mark ${IXGBESRC}
 	tar xf ${IXGBESRC}
 #	[ ! -e /lib/modules/${KVNAME}/build ] || rm /lib/modules/${KVNAME}/build
 	cd ${IXGBEDIR}; patch -p1 < ../ixgbe_4.10_compat.patch
+	cd ${IXGBEDIR}; patch -p1 < ../ixgbe_4.10_max-mtu.patch
 	cd ${IXGBEDIR}/src; make CFLAGS_EXTRA="-DIXGBE_NO_LRO" BUILD_KERNEL=${KVNAME} KSRC=${TOP}/${KERNEL_SRC}
 	cp ${IXGBEDIR}/src/ixgbe.ko ixgbe.ko
 

e1000e_4.10_max-mtu.patch

@@ -0,0 +1,37 @@
+diff --git a/src/netdev.c b/src/netdev.c
+index 73b0f9a..aef1bc2 100644
+--- a/src/netdev.c
++++ b/src/netdev.c
+@@ -6724,19 +6724,12 @@ static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
+ 	int max_frame = new_mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;
+ 
+ 	/* Jumbo frame support */
+-	if ((max_frame > (VLAN_ETH_FRAME_LEN + ETH_FCS_LEN)) &&
++	if ((new_mtu > ETH_DATA_LEN) &&
+ 	    !(adapter->flags & FLAG_HAS_JUMBO_FRAMES)) {
+ 		e_err("Jumbo Frames not supported.\n");
+ 		return -EINVAL;
+ 	}
+ 
+-	/* Supported frame sizes */
+-	if ((new_mtu < (VLAN_ETH_ZLEN + ETH_FCS_LEN)) ||
+-	    (max_frame > adapter->max_hw_frame_size)) {
+-		e_err("Unsupported MTU setting\n");
+-		return -EINVAL;
+-	}
+-
+ 	/* Jumbo frame workaround on 82579 and newer requires CRC be stripped */
+ 	if ((adapter->hw.mac.type >= e1000_pch2lan) &&
+ 	    !(adapter->flags2 & FLAG2_CRC_STRIPPING) &&
+@@ -8262,6 +8255,11 @@ static int e1000_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+ #endif /* HAVE_NETDEV_VLAN_FEATURES */
+ 	}
+ 
++	/* MTU range: 68 - max_hw_frame_size */
++	netdev->min_mtu = ETH_MIN_MTU;
++	netdev->max_mtu = adapter->max_hw_frame_size -
++	                  (VLAN_ETH_HLEN + ETH_FCS_LEN);
++
+ 	if (e1000e_enable_mng_pass_thru(&adapter->hw))
+ 		adapter->flags |= FLAG_MNG_PT_ENABLED;
+ 

igb_4.10_max-mtu.patch

@@ -0,0 +1,47 @@
+diff --git a/src/e1000_defines.h b/src/e1000_defines.h
+index 6de3988..d58e12f 100644
+--- a/src/e1000_defines.h
++++ b/src/e1000_defines.h
+@@ -423,7 +423,8 @@
+ #define ETHERNET_IEEE_VLAN_TYPE		0x8100  /* 802.3ac packet */
+ 
+ #define ETHERNET_FCS_SIZE		4
+-#define MAX_JUMBO_FRAME_SIZE		0x3F00
++#define MAX_JUMBO_FRAME_SIZE		0x2600
++#define MAX_STD_JUMBO_FRAME_SIZE	9216
+ /* The datasheet maximum supported RX size is 9.5KB (9728 bytes) */
+ #define MAX_RX_JUMBO_FRAME_SIZE		0x2600
+ #define E1000_TX_PTR_GAP		0x1F
+diff --git a/src/igb_main.c b/src/igb_main.c
+index 2dff0f4..bbfe87e 100644
+--- a/src/igb_main.c
++++ b/src/igb_main.c
+@@ -2852,6 +2852,10 @@ static int igb_probe(struct pci_dev *pdev,
+ 	if (pci_using_dac)
+ 		netdev->features |= NETIF_F_HIGHDMA;
+ 
++	/* MTU range: 68 - 9216 */
++	netdev->min_mtu = ETH_MIN_MTU;
++	netdev->max_mtu = MAX_STD_JUMBO_FRAME_SIZE;
++
+ 	adapter->en_mng_pt = e1000_enable_mng_pass_thru(hw);
+ #ifdef DEBUG
+ 	if (adapter->dmac != IGB_DMAC_DISABLE)
+@@ -5832,17 +5836,6 @@ static int igb_change_mtu(struct net_device *netdev, int new_mtu)
+ 	struct pci_dev *pdev = adapter->pdev;
+ 	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
+ 
+-	if ((new_mtu < 68) || (max_frame > MAX_JUMBO_FRAME_SIZE)) {
+-		dev_err(pci_dev_to_dev(pdev), "Invalid MTU setting\n");
+-		return -EINVAL;
+-	}
+-
+-#define MAX_STD_JUMBO_FRAME_SIZE 9238
+-	if (max_frame > MAX_STD_JUMBO_FRAME_SIZE) {
+-		dev_err(pci_dev_to_dev(pdev), "MTU > 9216 not supported.\n");
+-		return -EINVAL;
+-	}
+-
+ 	/* adjust max frame to be at least the size of a standard frame */
+ 	if (max_frame < (ETH_FRAME_LEN + ETH_FCS_LEN))
+ 		max_frame = ETH_FRAME_LEN + ETH_FCS_LEN;

ixgbe_4.10_max-mtu.patch

@@ -0,0 +1,37 @@
+diff --git a/src/ixgbe_main.c b/src/ixgbe_main.c
+index 83c6250..fe226cd 100644
+--- a/src/ixgbe_main.c
++++ b/src/ixgbe_main.c
+@@ -6379,11 +6379,6 @@ static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter)
+ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
+ {
+ 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
+-	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+-
+-	/* MTU < 68 is an error and causes problems on some kernels */
+-	if ((new_mtu < 68) || (max_frame > IXGBE_MAX_JUMBO_FRAME_SIZE))
+-		return -EINVAL;
+ 
+ 	/*
+ 	 * For 82599EB we cannot allow legacy VFs to enable their receive
+@@ -6392,7 +6387,7 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
+ 	 */
+ 	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) &&
+ 	    (adapter->hw.mac.type == ixgbe_mac_82599EB) &&
+-	    (max_frame > (ETH_FRAME_LEN + ETH_FCS_LEN)))
++	    (new_mtu > ETH_DATA_LEN))
+ 		e_warn(probe, "Setting MTU > 1500 will disable legacy VFs\n");
+ 
+ 	e_info(probe, "changing MTU from %d to %d\n", netdev->mtu, new_mtu);
+@@ -10134,6 +10129,11 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
+ #ifdef IFF_SUPP_NOFCS
+ 	netdev->priv_flags |= IFF_SUPP_NOFCS;
+ #endif
++
++	/* MTU range: 68 - 9710 */
++	netdev->min_mtu = ETH_MIN_MTU;
++	netdev->max_mtu = IXGBE_MAX_JUMBO_FRAME_SIZE - (ETH_HLEN + ETH_FCS_LEN);
++
+ #if IS_ENABLED(CONFIG_DCB)
+ 	if (adapter->flags & IXGBE_FLAG_DCB_CAPABLE)
+ 		netdev->dcbnl_ops = &dcbnl_ops;