[PATCH net 2/3] net: lan966x: Adjust maximum frame size when vlan is enabled/disabled

From: Horatiu Vultur
Date: Sun Oct 23 2022 - 14:45:30 EST


When vlan filtering is enabled/disabled, it is required to adjust the
maximum received frame size that it can received. When vlan filtering is
enabled, it would all to receive extra 4 bytes, that are the vlan tag.
So the maximum frame size would be 1522 with a vlan tag. If vlan
filtering is disabled then the maximum frame size would be 1518
regardless if there is or not a vlan tag.

Fixes: 6d2c186afa5d ("net: lan966x: Add vlan support.")
Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
---
.../net/ethernet/microchip/lan966x/lan966x_regs.h | 15 +++++++++++++++
.../net/ethernet/microchip/lan966x/lan966x_vlan.c | 6 ++++++
2 files changed, 21 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
index 1d90b93dd417a..fb5087fef22e1 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_regs.h
@@ -585,6 +585,21 @@ enum lan966x_target {
#define DEV_MAC_MAXLEN_CFG_MAX_LEN_GET(x)\
FIELD_GET(DEV_MAC_MAXLEN_CFG_MAX_LEN, x)

+/* DEV:MAC_CFG_STATUS:MAC_TAGS_CFG */
+#define DEV_MAC_TAGS_CFG(t) __REG(TARGET_DEV, t, 8, 28, 0, 1, 44, 12, 0, 1, 4)
+
+#define DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA BIT(1)
+#define DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA_SET(x)\
+ FIELD_PREP(DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA, x)
+#define DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA_GET(x)\
+ FIELD_GET(DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA, x)
+
+#define DEV_MAC_TAGS_CFG_VLAN_AWR_ENA BIT(0)
+#define DEV_MAC_TAGS_CFG_VLAN_AWR_ENA_SET(x)\
+ FIELD_PREP(DEV_MAC_TAGS_CFG_VLAN_AWR_ENA, x)
+#define DEV_MAC_TAGS_CFG_VLAN_AWR_ENA_GET(x)\
+ FIELD_GET(DEV_MAC_TAGS_CFG_VLAN_AWR_ENA, x)
+
/* DEV:MAC_CFG_STATUS:MAC_IFG_CFG */
#define DEV_MAC_IFG_CFG(t) __REG(TARGET_DEV, t, 8, 28, 0, 1, 44, 20, 0, 1, 4)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_vlan.c b/drivers/net/ethernet/microchip/lan966x/lan966x_vlan.c
index 8d7260cd7da9c..3c44660128dae 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_vlan.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_vlan.c
@@ -169,6 +169,12 @@ void lan966x_vlan_port_apply(struct lan966x_port *port)
ANA_VLAN_CFG_VLAN_POP_CNT,
lan966x, ANA_VLAN_CFG(port->chip_port));

+ lan_rmw(DEV_MAC_TAGS_CFG_VLAN_AWR_ENA_SET(port->vlan_aware) |
+ DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA_SET(port->vlan_aware),
+ DEV_MAC_TAGS_CFG_VLAN_AWR_ENA |
+ DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA,
+ lan966x, DEV_MAC_TAGS_CFG(port->chip_port));
+
/* Drop frames with multicast source address */
val = ANA_DROP_CFG_DROP_MC_SMAC_ENA_SET(1);
if (port->vlan_aware && !pvid)
--
2.38.0