The CPSW switchdev driver inherited fix from commit 9421c9015047 ("net: ethernet: ti: cpsw: fix min eth packet size") which changes min TX packet size to 64bytes (VLAN_ETH_ZLEN, excluding ETH_FCS). It was done to fix HW packed drop issue when packets are sent from Host to the port with PVID and un-tagging enabled. Unfortunately this breaks some other non-switch specific use-cases, like: - [1] CPSW port as DSA CPU port with DSA-tag applied at the end of the packet - [2] Some industrial protocols, which expects min TX packet size 60Bytes (excluding FCS).

Fix it by configuring min TX packet size depending driver mode - 60Bytes (ETH_ZLEN) for multi mac (dual-mac) mode - 64Bytes (VLAN_ETH_ZLEN) for switch mode

[1] https://lore.kernel.org/netdev/20210531124051.GA15218@cephalopod/ [2] https://e2e.ti.com/support/arm/sitara_arm/f/791/t/701669

Cc: Ben Hutchings ben.hutchings@essensium.com Cc: stable@vger.kernel.org Fixes: ed3525eda4c4 ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac") Signed-off-by: Grygorii Strashko grygorii.strashko@ti.com --- drivers/net/ethernet/ti/cpsw_new.c | 12 +++++++++--- drivers/net/ethernet/ti/cpsw_priv.h | 4 +++- 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw_new.c b/drivers/net/ethernet/ti/cpsw_new.c index 11f536138495..401909bff319 100644 --- a/drivers/net/ethernet/ti/cpsw_new.c +++ b/drivers/net/ethernet/ti/cpsw_new.c @@ -918,14 +918,17 @@ static netdev_tx_t cpsw_ndo_start_xmit(struct sk_buff *skb, struct cpts *cpts = cpsw->cpts; struct netdev_queue *txq; struct cpdma_chan *txch; + unsigned int len; int ret, q_idx;

- if (skb_padto(skb, CPSW_MIN_PACKET_SIZE)) { + if (skb_padto(skb, priv->tx_packet_min)) { cpsw_err(priv, tx_err, "packet pad failed\n"); ndev->stats.tx_dropped++; return NET_XMIT_DROP; }

+ len = skb->len < priv->tx_packet_min ? priv->tx_packet_min : skb->len; + if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP && priv->tx_ts_enabled && cpts_can_timestamp(cpts, skb)) skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; @@ -937,7 +940,7 @@ static netdev_tx_t cpsw_ndo_start_xmit(struct sk_buff *skb, txch = cpsw->txv[q_idx].ch; txq = netdev_get_tx_queue(ndev, q_idx); skb_tx_timestamp(skb); - ret = cpdma_chan_submit(txch, skb, skb->data, skb->len, + ret = cpdma_chan_submit(txch, skb, skb->data, len, priv->emac_port); if (unlikely(ret != 0)) { cpsw_err(priv, tx_err, "desc submit failed\n"); @@ -1100,7 +1103,7 @@ static int cpsw_ndo_xdp_xmit(struct net_device *ndev, int n,

for (i = 0; i < n; i++) { xdpf = frames[i]; - if (xdpf->len < CPSW_MIN_PACKET_SIZE) + if (xdpf->len < priv->tx_packet_min) break;

if (cpsw_xdp_tx_frame(priv, xdpf, NULL, priv->emac_port)) @@ -1389,6 +1392,7 @@ static int cpsw_create_ports(struct cpsw_common *cpsw) priv->dev = dev; priv->msg_enable = netif_msg_init(debug_level, CPSW_DEBUG); priv->emac_port = i + 1; + priv->tx_packet_min = CPSW_MIN_PACKET_SIZE;

if (is_valid_ether_addr(slave_data->mac_addr)) { ether_addr_copy(priv->mac_addr, slave_data->mac_addr); @@ -1686,6 +1690,7 @@ static int cpsw_dl_switch_mode_set(struct devlink *dl, u32 id,

priv = netdev_priv(sl_ndev); slave->port_vlan = vlan; + priv->tx_packet_min = CPSW_MIN_PACKET_SIZE_VLAN; if (netif_running(sl_ndev)) cpsw_port_add_switch_def_ale_entries(priv, slave); @@ -1714,6 +1719,7 @@ static int cpsw_dl_switch_mode_set(struct devlink *dl, u32 id,

priv = netdev_priv(slave->ndev); slave->port_vlan = slave->data->dual_emac_res_vlan; + priv->tx_packet_min = CPSW_MIN_PACKET_SIZE; cpsw_port_add_dual_emac_def_ale_entries(priv, slave); }

diff --git a/drivers/net/ethernet/ti/cpsw_priv.h b/drivers/net/ethernet/ti/cpsw_priv.h index a323bea54faa..2951fb7b9dae 100644 --- a/drivers/net/ethernet/ti/cpsw_priv.h +++ b/drivers/net/ethernet/ti/cpsw_priv.h @@ -89,7 +89,8 @@ do { \

#define CPSW_POLL_WEIGHT 64 #define CPSW_RX_VLAN_ENCAP_HDR_SIZE 4 -#define CPSW_MIN_PACKET_SIZE (VLAN_ETH_ZLEN) +#define CPSW_MIN_PACKET_SIZE_VLAN (VLAN_ETH_ZLEN) +#define CPSW_MIN_PACKET_SIZE (ETH_ZLEN) #define CPSW_MAX_PACKET_SIZE (VLAN_ETH_FRAME_LEN +\ ETH_FCS_LEN +\ CPSW_RX_VLAN_ENCAP_HDR_SIZE) @@ -380,6 +381,7 @@ struct cpsw_priv { u32 emac_port; struct cpsw_common *cpsw; int offload_fwd_mark; + u32 tx_packet_min; };

#define ndev_to_cpsw(ndev) (((struct cpsw_priv *)netdev_priv(ndev))->cpsw)