kernel: backport MediaTek jumbo frame support

Allow MTU up to 2026 on mediatek, ramips/mt7621 targets.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>

1 files changed, 36 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.10/763-v5.11-net-dsa-mt7530-enable-MTU-normalization.patch b/target/linux/generic/backport-5.10/763-v5.11-net-dsa-mt7530-enable-MTU-normalization.patch
new file mode 100644
index 0000000000..b0ad7b9f87
--- /dev/null
+++ b/target/linux/generic/backport-5.10/763-v5.11-net-dsa-mt7530-enable-MTU-normalization.patch
@@ -0,0 +1,36 @@
+From 771c8901568dd8776a260aa93db41be88a60389e Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Fri, 11 Dec 2020 01:03:22 +0800
+Subject: [PATCH] net: dsa: mt7530: enable MTU normalization
+
+MT7530 has a global RX length register, so we are actually changing its
+MRU.
+Enable MTU normalization for this reason.
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+Acked-by: Landen Chao <landen.chao@mediatek.com>
+Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
+Link: https://lore.kernel.org/r/20201210170322.3433-1-dqfext@gmail.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/dsa/mt7530.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -1703,6 +1703,7 @@ mt7530_setup(struct dsa_switch *ds)
+ 	 */
+ 	dn = dsa_to_port(ds, MT7530_CPU_PORT)->master->dev.of_node->parent;
+ 	ds->configure_vlan_while_not_filtering = true;
++	ds->mtu_enforcement_ingress = true;
+ 
+ 	if (priv->id == ID_MT7530) {
+ 		regulator_set_voltage(priv->core_pwr, 1000000, 1000000);
+@@ -1947,6 +1948,7 @@ mt7531_setup(struct dsa_switch *ds)
+ 	}
+ 
+ 	ds->configure_vlan_while_not_filtering = true;
++	ds->mtu_enforcement_ingress = true;
+ 
+ 	/* Flush the FDB table */
+ 	ret = mt7530_fdb_cmd(priv, MT7530_FDB_FLUSH, NULL);