[PATCH net-next v2 1/3] net: stmmac: fpe: Enforce pmac_enabled in set_mm and keep it on at init
From: <hidden>
Date: 2026-08-03 03:24:26
Also in:
linux-arm-kernel, lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
From: Nazim Amirul <redacted> The preemptive MAC in DWMAC is always enabled, meaning DWMAC is always ready to receive preemptive mPackets. Initialize pmac_enabled to true at init time and reject attempts to disable it via ethtool set_mm. Also add a missing fpesel capability check in stmmac_set_mm() to return -EOPNOTSUPP early on hardware without FPE support. Signed-off-by: Rohan G Thomas <redacted> Signed-off-by: Nazim Amirul <redacted> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> --- v2: No changes. Collect Reviewed-by from Maxime Chevallier. drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 7 +++++++ drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c | 5 +++++ 2 files changed, 12 insertions(+)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 92585d27ab88..8ebdd249e5c8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c@@ -1064,6 +1064,13 @@ static int stmmac_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg, if (err) return err; + if (!priv->dma_cap.fpesel) + return -EOPNOTSUPP; + + /* DWMAC always have preemptible MAC enabled */ + if (!cfg->pmac_enabled) + return -EINVAL; + stmmac_fpe_set_add_frag_size(priv, frag_size); ethtool_mmsv_set_mm(&priv->fpe_cfg.mmsv, cfg);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
index c54c70224351..2f880c5e35b0 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_fpe.c@@ -176,6 +176,11 @@ void stmmac_fpe_init(struct stmmac_priv *priv) if ((!priv->fpe_cfg.reg || !priv->hw->mac->fpe_map_preemption_class) && priv->dma_cap.fpesel) dev_info(priv->device, "FPE is not supported by driver.\n"); + + /* The preemptive MAC in DWMAC is always enabled, so initialize + * pmac_enabled to true to reflect the hardware state. + */ + priv->fpe_cfg.mmsv.pmac_enabled = true; } int stmmac_fpe_get_add_frag_size(struct stmmac_priv *priv)
--
2.43.7