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From:   Horatiu Vultur <horatiu.vultur@microchip.com>
To:     <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>, <UNGLinuxDriver@microchip.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>
Subject: [PATCH net v2 2/3] net: lan966x: Adjust maximum frame size when vlan is enabled/disabled
Date:   Sun, 30 Oct 2022 22:36:35 +0100
Message-ID: <20221030213636.1031408-3-horatiu.vultur@microchip.com>
In-Reply-To: <20221030213636.1031408-1-horatiu.vultur@microchip.com>
References: <20221030213636.1031408-1-horatiu.vultur@microchip.com>
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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@microchip.com>
---
 .../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