[PATCH net v2] net: stmmac: keep gso_enabled_types in sync with netdev features
From: Lorenzo Bianconi <hidden>
Date: 2026-08-12 04:38:52
Also in:
netdev
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
stmmac_set_gso_types() derives priv->gso_enabled_types all-or-nothing
from NETIF_F_TSO, but stmmac_set_gso_features() advertises NETIF_F_TSO,
NETIF_F_TSO6 and (on GMAC4) NETIF_F_GSO_UDP_L4 as independently
toggleable features. Since netdev_fix_features() only ties TSO6 to the
checksum features, disabling TSO (ethtool -K ethX tx-tcp-segmentation
off) leaves TSO6 enabled in dev->features while gso_enabled_types
becomes 0.
For a TCPv6 GSO skb the stack then keeps the frame unsegmented
(NETIF_F_TSO6 is still set), stmmac_features_check() does not clear the
GSO mask, and the stmmac_xmit() gate (gso_type & gso_enabled_types) is
false, so the multi-MSS skb is transmitted through the ordinary
descriptor path as a single oversized frame.
Derive each GSO type from its own feature bit instead, so the mask stays
in sync with dev->features and TCPv6 (or UDP L4 on GMAC4) segmentation
keeps working when only TSO is disabled.
Fixes: 9edfa7dab811 ("net: stmmac: enable TSO for IPv6")
Signed-off-by: Lorenzo Bianconi <redacted>
---
Changes in v2:
- Fix possible race between stmmac_set_gso_types() and stmmac_xmit().
- Fix fixes tag.
- Link to v1: https://lore.kernel.org/r/20260808-stmmac-fix-tso6-features-v1-1-f82b17595052@oss.qualcomm.com (local)
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 28 +++++++++++++----------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index a71f0df26378..df3549f55741 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c@@ -4371,16 +4371,20 @@ static void stmmac_flush_tx_descriptors(struct stmmac_priv *priv, int queue) stmmac_set_queue_tx_tail_ptr(priv, tx_q, queue, tx_q->cur_tx); } -static void stmmac_set_gso_types(struct stmmac_priv *priv, bool tso) +static void stmmac_set_gso_types(struct stmmac_priv *priv, + netdev_features_t features) { - if (!tso) { - priv->gso_enabled_types = 0; - } else { - /* Manage oversized TCP frames for GMAC4 device */ - priv->gso_enabled_types = SKB_GSO_TCPV4 | SKB_GSO_TCPV6; - if (priv->plat->core_type == DWMAC_CORE_GMAC4) - priv->gso_enabled_types |= SKB_GSO_UDP_L4; - } + unsigned int gso_types = 0; + + if (features & NETIF_F_TSO) + gso_types |= SKB_GSO_TCPV4; + if (features & NETIF_F_TSO6) + gso_types |= SKB_GSO_TCPV6; + /* Manage oversized UDP frames for GMAC4 devices */ + if (features & NETIF_F_GSO_UDP_L4) + gso_types |= SKB_GSO_UDP_L4; + + WRITE_ONCE(priv->gso_enabled_types, gso_types); } static void stmmac_set_gso_features(struct net_device *ndev)
@@ -4416,7 +4420,7 @@ static void stmmac_set_gso_features(struct net_device *ndev) if (priv->plat->core_type == DWMAC_CORE_GMAC4) ndev->hw_features |= NETIF_F_GSO_UDP_L4; - stmmac_set_gso_types(priv, true); + stmmac_set_gso_types(priv, ndev->hw_features); dev_info(priv->device, "TSO feature enabled\n"); }
@@ -4766,7 +4770,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) stmmac_stop_sw_lpi(priv); if (skb_is_gso(skb) && - skb_shinfo(skb)->gso_type & priv->gso_enabled_types) + (skb_shinfo(skb)->gso_type & READ_ONCE(priv->gso_enabled_types))) return stmmac_tso_xmit(skb, dev); if (priv->est && priv->est->enable &&
@@ -6198,7 +6202,7 @@ static int stmmac_set_features(struct net_device *netdev, stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan); } - stmmac_set_gso_types(priv, features & NETIF_F_TSO); + stmmac_set_gso_types(priv, features); if (features & NETIF_F_HW_VLAN_CTAG_RX) priv->hw->hw_vlan_en = true;
--- base-commit: 7b53449540502cb21b32bca62a6258e22cd97bbe change-id: 20260808-stmmac-fix-tso6-features-7fdc5e9448e2 Best regards, -- Lorenzo Bianconi [off-list ref]