From: Grygorii Strashko grygorii.strashko@ti.com
commit acc68b8d2a1196c4db806947606f162dbeed2274 upstream.
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 on driver mode - 60Bytes (ETH_ZLEN) for multi mac (dual-mac) mode - 64Bytes (VLAN_ETH_ZLEN) for switch mode and update it during driver mode change and annotate with READ_ONCE()/WRITE_ONCE() as it can be read by napi while writing.
[1] https://lore.kernel.org/netdev/20210531124051.GA15218@cephalopod/ [2] https://e2e.ti.com/support/arm/sitara_arm/f/791/t/701669
Cc: stable@vger.kernel.org Fixes: ed3525eda4c4 ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac") Reported-by: Ben Hutchings ben.hutchings@essensium.com Signed-off-by: Grygorii Strashko grygorii.strashko@ti.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/ti/cpsw_new.c | 7 +++++-- drivers/net/ethernet/ti/cpsw_priv.h | 4 +++- 2 files changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/net/ethernet/ti/cpsw_new.c +++ b/drivers/net/ethernet/ti/cpsw_new.c @@ -928,7 +928,7 @@ static netdev_tx_t cpsw_ndo_start_xmit(s struct cpdma_chan *txch; int ret, q_idx;
- if (skb_padto(skb, CPSW_MIN_PACKET_SIZE)) { + if (skb_put_padto(skb, READ_ONCE(priv->tx_packet_min))) { cpsw_err(priv, tx_err, "packet pad failed\n"); ndev->stats.tx_dropped++; return NET_XMIT_DROP; @@ -1108,7 +1108,7 @@ static int cpsw_ndo_xdp_xmit(struct net_
for (i = 0; i < n; i++) { xdpf = frames[i]; - if (xdpf->len < CPSW_MIN_PACKET_SIZE) { + if (xdpf->len < READ_ONCE(priv->tx_packet_min)) { xdp_return_frame_rx_napi(xdpf); drops++; continue; @@ -1402,6 +1402,7 @@ static int cpsw_create_ports(struct 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); @@ -1699,6 +1700,7 @@ static int cpsw_dl_switch_mode_set(struc
priv = netdev_priv(sl_ndev); slave->port_vlan = vlan; + WRITE_ONCE(priv->tx_packet_min, CPSW_MIN_PACKET_SIZE_VLAN); if (netif_running(sl_ndev)) cpsw_port_add_switch_def_ale_entries(priv, slave); @@ -1727,6 +1729,7 @@ static int cpsw_dl_switch_mode_set(struc
priv = netdev_priv(slave->ndev); slave->port_vlan = slave->data->dual_emac_res_vlan; + WRITE_ONCE(priv->tx_packet_min, CPSW_MIN_PACKET_SIZE); cpsw_port_add_dual_emac_def_ale_entries(priv, slave); }
--- 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)