From d8afae0be8f0a2a4a26e303dd5212e2a2f8d69a3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Fri, 12 Feb 2021 16:28:57 +0100 Subject: [PATCH] bcm4908: fix handling Ethernet frames of size 1506 - 1514 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MTU needs to be explicitly set as default value is too low. Signed-off-by: Rafał Miłecki --- ...4908_enet-set-MTU-on-open-on-request.patch | 113 ++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 target/linux/bcm4908/patches-5.4/170-net-broadcom-bcm4908_enet-set-MTU-on-open-on-request.patch diff --git a/target/linux/bcm4908/patches-5.4/170-net-broadcom-bcm4908_enet-set-MTU-on-open-on-request.patch b/target/linux/bcm4908/patches-5.4/170-net-broadcom-bcm4908_enet-set-MTU-on-open-on-request.patch new file mode 100644 index 00000000000..87cb8510345 --- /dev/null +++ b/target/linux/bcm4908/patches-5.4/170-net-broadcom-bcm4908_enet-set-MTU-on-open-on-request.patch @@ -0,0 +1,113 @@ +From d7dfbcba0437955ccbe4c6db736526d528f27720 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= +Date: Fri, 12 Feb 2021 16:06:00 +0100 +Subject: [PATCH] net: broadcom: bcm4908_enet: set MTU on open & on request + +Hardware comes up with default max frame size set to 1518. When using it +with switch it results in actual Ethernet MTU 1492: +1518 - 14 (Ethernet header) - 4 (Broadcom's tag) - 4 (802.1q) - 4 (FCS) + +Above means hardware in its default state can't handle standard Ethernet +traffic (MTU 1500). + +Define maximum possible Ethernet overhead and always set MAC max frame +length accordingly. This change fixes handling Ethernet frames of length +1506 - 1514. +--- + drivers/net/ethernet/broadcom/bcm4908_enet.c | 31 ++++++++++++++++---- + 1 file changed, 25 insertions(+), 6 deletions(-) + +--- a/drivers/net/ethernet/broadcom/bcm4908_enet.c ++++ b/drivers/net/ethernet/broadcom/bcm4908_enet.c +@@ -5,6 +5,7 @@ + + #include + #include ++#include + #include + #include + #include +@@ -29,9 +30,10 @@ + ENET_DMA_CH_CFG_INT_BUFF_DONE) + #define ENET_DMA_MAX_BURST_LEN 8 /* in 64 bit words */ + +-#define ENET_MTU_MIN 60 +-#define ENET_MTU_MAX 1500 /* Is it possible to support 2044? */ +-#define ENET_MTU_MAX_EXTRA_SIZE 32 /* L2 */ ++#define ENET_MTU_MAX ETH_DATA_LEN /* Is it possible to support 2044? */ ++#define BRCM_MAX_TAG_LEN 6 ++#define ENET_MAX_ETH_OVERHEAD (ETH_HLEN + BRCM_MAX_TAG_LEN + VLAN_HLEN + \ ++ ETH_FCS_LEN + 4) /* 32 */ + + struct bcm4908_enet_dma_ring_bd { + __le32 ctl; +@@ -135,6 +137,11 @@ static void bcm4908_enet_intrs_ack(struc + enet_write(enet, ENET_DMA_CH_RX_CFG + ENET_DMA_CH_CFG_INT_STAT, ENET_DMA_INT_DEFAULTS); + } + ++static void bcm4908_enet_set_mtu(struct bcm4908_enet *enet, int mtu) ++{ ++ enet_umac_write(enet, UMAC_MAX_FRAME_LEN, mtu + ENET_MAX_ETH_OVERHEAD); ++} ++ + /*** + * DMA + */ +@@ -246,7 +253,7 @@ static int bcm4908_enet_dma_alloc_rx_buf + u32 tmp; + int err; + +- slot->len = ENET_MTU_MAX + ENET_MTU_MAX_EXTRA_SIZE; ++ slot->len = ENET_MTU_MAX + ENET_MAX_ETH_OVERHEAD; + + slot->skb = netdev_alloc_skb(enet->netdev, slot->len); + if (!slot->skb) +@@ -374,6 +381,8 @@ static void bcm4908_enet_gmac_init(struc + { + u32 cmd; + ++ bcm4908_enet_set_mtu(enet, enet->netdev->mtu); ++ + cmd = enet_umac_read(enet, UMAC_CMD); + enet_umac_write(enet, UMAC_CMD, cmd | CMD_SW_RESET); + enet_umac_write(enet, UMAC_CMD, cmd & ~CMD_SW_RESET); +@@ -559,7 +568,7 @@ static int bcm4908_enet_poll(struct napi + + len = (ctl & DMA_CTL_LEN_DESC_BUFLENGTH) >> DMA_CTL_LEN_DESC_BUFLENGTH_SHIFT; + +- if (len < ENET_MTU_MIN || ++ if (len < ETH_ZLEN || + (ctl & (DMA_CTL_STATUS_SOP | DMA_CTL_STATUS_EOP)) != (DMA_CTL_STATUS_SOP | DMA_CTL_STATUS_EOP)) { + enet->netdev->stats.rx_dropped++; + break; +@@ -583,11 +592,21 @@ static int bcm4908_enet_poll(struct napi + return handled; + } + ++static int bcm4908_enet_change_mtu(struct net_device *netdev, int new_mtu) ++{ ++ struct bcm4908_enet *enet = netdev_priv(netdev); ++ ++ bcm4908_enet_set_mtu(enet, new_mtu); ++ ++ return 0; ++} ++ + static const struct net_device_ops bcm4908_enet_netdev_ops = { + .ndo_open = bcm4908_enet_open, + .ndo_stop = bcm4908_enet_stop, + .ndo_start_xmit = bcm4908_enet_start_xmit, + .ndo_set_mac_address = eth_mac_addr, ++ .ndo_change_mtu = bcm4908_enet_change_mtu, + }; + + static int bcm4908_enet_probe(struct platform_device *pdev) +@@ -625,7 +644,7 @@ static int bcm4908_enet_probe(struct pla + eth_hw_addr_random(netdev); + netdev->netdev_ops = &bcm4908_enet_netdev_ops; + netdev->min_mtu = ETH_ZLEN; +- netdev->mtu = ENET_MTU_MAX; ++ netdev->mtu = ETH_DATA_LEN; + netdev->max_mtu = ENET_MTU_MAX; + netif_napi_add(netdev, &enet->napi, bcm4908_enet_poll, 64); +