Subject: [PATCH v2 net-next 05/10] bgmac: Add DMA support to handle frames beyond 8192 bytes

From: Vladimir Oltean <[email-masked]>
Date: Wed, 25 Mar 2020 17:22:04 +0200

From: Murali Krishna Policharla <[email-masked]>

Add DMA support in driver to handle jumbo frames beyond 8192 bytes.
Also update jumbo frame max size to include FCS, the DMA packet length
received includes FCS.

Signed-off-by: Murali Krishna Policharla <[email-masked]>
Reviewed-by: Arun Parameswaran <[email-masked]>
Signed-off-by: Vladimir Oltean <[email-masked]>
---
 drivers/net/ethernet/broadcom/bgmac.c | 4 +++-
 drivers/net/ethernet/broadcom/bgmac.h | 6 +++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c
index c530dff0353b..98ec1b8a7d8e 100644
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -1538,7 +1538,9 @@ int bgmac_enet_probe(struct bgmac *bgmac)
 	net_dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
 	net_dev->hw_features = net_dev->features;
 	net_dev->vlan_features = net_dev->features;
-	net_dev->max_mtu = BGMAC_RX_MAX_FRAME_SIZE;
+
+	/* Omit FCS from max MTU size */
+	net_dev->max_mtu = BGMAC_RX_MAX_FRAME_SIZE - ETH_FCS_LEN;
 
 	err = register_netdev(bgmac->net_dev);
 	if (err) {
diff --git a/drivers/net/ethernet/broadcom/bgmac.h b/drivers/net/ethernet/broadcom/bgmac.h
index 041ad069b5c8..351c598a3ec6 100644
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -351,7 +351,7 @@
 #define BGMAC_DESC_CTL0_IOC			0x20000000	/* IRQ on complete */
 #define BGMAC_DESC_CTL0_EOF			0x40000000	/* End of frame */
 #define BGMAC_DESC_CTL0_SOF			0x80000000	/* Start of frame */
-#define BGMAC_DESC_CTL1_LEN			0x00001FFF
+#define BGMAC_DESC_CTL1_LEN			0x00003FFF
 
 #define BGMAC_PHY_NOREGS			BRCM_PSEUDO_PHY_ADDR
 #define BGMAC_PHY_MASK				0x1F
@@ -366,8 +366,8 @@
 #define BGMAC_RX_FRAME_OFFSET			30		/* There are 2 unused bytes between header and real data */
 #define BGMAC_RX_BUF_OFFSET			(NET_SKB_PAD + NET_IP_ALIGN - \
 						 BGMAC_RX_FRAME_OFFSET)
-/* Jumbo frame size */
-#define BGMAC_RX_MAX_FRAME_SIZE			9720
+/* Jumbo frame size with FCS */
+#define BGMAC_RX_MAX_FRAME_SIZE			9724
 #define BGMAC_RX_BUF_SIZE			(BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE)
 #define BGMAC_RX_ALLOC_SIZE			(SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \
 						 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
-- 
2.17.1