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authorHoratiu Vultur <horatiu.vultur@microchip.com>2022-10-30 22:36:34 +0100
committerJakub Kicinski <kuba@kernel.org>2022-11-01 21:18:16 -0700
commit486c292230166c2d61701d3c984bf9143588ea28 (patch)
tree9e929dcce1865a48100731e2ca1f28e6fbcd5b8a /drivers
parent6c412da54c80a54b1a8b7f89677f6e82f0fabec4 (diff)
net: lan966x: Fix the MTU calculation
When the MTU was changed, the lan966x didn't take in consideration the L2 header and the FCS. So the HW was configured with a smaller value than what was desired. Therefore the correct value to configure the HW would be new_mtu + ETH_HLEN + ETH_FCS_LEN. The vlan tag is not considered here, because at the time when the blamed commit was added, there was no vlan filtering support. The vlan fix will be part of the next patch. Fixes: d28d6d2e37d1 ("net: lan966x: add port module support") Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ethernet/microchip/lan966x/lan966x_main.c2
-rw-r--r--drivers/net/ethernet/microchip/lan966x/lan966x_main.h2
2 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
index be2fd030cccb..b3070c3fcad0 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.c
@@ -386,7 +386,7 @@ static int lan966x_port_change_mtu(struct net_device *dev, int new_mtu)
int old_mtu = dev->mtu;
int err;
- lan_wr(DEV_MAC_MAXLEN_CFG_MAX_LEN_SET(new_mtu),
+ lan_wr(DEV_MAC_MAXLEN_CFG_MAX_LEN_SET(LAN966X_HW_MTU(new_mtu)),
lan966x, DEV_MAC_MAXLEN_CFG(port->chip_port));
dev->mtu = new_mtu;
diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
index 9656071b8289..4ec33999e4df 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_main.h
@@ -26,6 +26,8 @@
#define LAN966X_BUFFER_MEMORY (160 * 1024)
#define LAN966X_BUFFER_MIN_SZ 60
+#define LAN966X_HW_MTU(mtu) ((mtu) + ETH_HLEN + ETH_FCS_LEN)
+
#define PGID_AGGR 64
#define PGID_SRC 80
#define PGID_ENTRIES 89