[PATCH net 1/5] net: stmmac: Remove VLAN perfect matching dead code
From: Ovidiu Panait
Date: Wed Jul 29 2026 - 06:09:26 EST
stmmac_vlan_update() falls back to "perfect matching" when the VLAN hash
filter is unavailable (!priv->dma_cap.vlhash). This fallback has been
unreachable in normal operation since its introduction in
commit c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if
HASH is not available") because the NETIF_F_HW_VLAN_{CTAG,STAG}_FILTER
features are advertised only when priv->dma_cap.vlhash is true.
The fallback is also duplicating the code in vlan_add_hw_rx_fltr(), which
is always available since stmmac_get_num_vlan() returns at least 1.
Therefore, remove it.
Fixes: c7ab0b8088d7 ("net: stmmac: Fallback to VLAN Perfect filtering if HASH is not available")
Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@xxxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/hwif.h | 2 +-
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 13 +-----
.../net/ethernet/stmicro/stmmac/stmmac_vlan.c | 41 +------------------
3 files changed, 4 insertions(+), 52 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 04dafec021b4..6f26dbf95ce1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -633,7 +633,7 @@ struct stmmac_est_ops {
struct stmmac_vlan_ops {
/* VLAN */
void (*update_vlan_hash)(struct mac_device_info *hw, u32 hash,
- u16 perfect_match, bool is_double);
+ bool is_double);
void (*enable_vlan)(struct mac_device_info *hw, u32 type);
void (*rx_hw_vlan)(struct mac_device_info *hw, struct dma_desc *rx_desc,
struct sk_buff *skb);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 0de4bc949913..fc9f1342ea45 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6791,29 +6791,18 @@ static u32 stmmac_vid_crc32_le(__le16 vid_le)
static int stmmac_vlan_update(struct stmmac_priv *priv, bool is_double)
{
u32 crc, hash = 0;
- u16 pmatch = 0;
- int count = 0;
u16 vid = 0;
for_each_set_bit(vid, priv->active_vlans, VLAN_N_VID) {
__le16 vid_le = cpu_to_le16(vid);
crc = bitrev32(~stmmac_vid_crc32_le(vid_le)) >> 28;
hash |= (1 << crc);
- count++;
- }
-
- if (!priv->dma_cap.vlhash) {
- if (count > 2) /* VID = 0 always passes filter */
- return -EOPNOTSUPP;
-
- pmatch = vid;
- hash = 0;
}
if (!netif_running(priv->dev))
return 0;
- return stmmac_update_vlan_hash(priv, priv->hw, hash, pmatch, is_double);
+ return stmmac_update_vlan_hash(priv, priv->hw, hash, is_double);
}
/* FIXME: This may need RXC to be running, but it may be called with BH
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_vlan.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_vlan.c
index e24efe3bfedb..983a90cb9767 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_vlan.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_vlan.c
@@ -162,7 +162,7 @@ static void vlan_restore_hw_rx_fltr(struct net_device *dev,
}
static void vlan_update_hash(struct mac_device_info *hw, u32 hash,
- u16 perfect_match, bool is_double)
+ bool is_double)
{
void __iomem *ioaddr = hw->pcsr;
u32 value;
@@ -184,20 +184,6 @@ static void vlan_update_hash(struct mac_device_info *hw, u32 hash,
}
writel(value, ioaddr + VLAN_TAG);
- } else if (perfect_match) {
- u32 value = VLAN_ETV;
-
- if (is_double) {
- value |= VLAN_EDVLP;
- value |= VLAN_ESVL;
- value |= VLAN_DOVLTC;
- } else {
- value &= ~VLAN_EDVLP;
- value &= ~VLAN_ESVL;
- value &= ~VLAN_DOVLTC;
- }
-
- writel(value | perfect_match, ioaddr + VLAN_TAG);
} else {
value &= ~(VLAN_VTHM | VLAN_ETV);
value &= ~(VLAN_EDVLP | VLAN_ESVL);
@@ -251,7 +237,7 @@ static void vlan_set_hw_mode(struct mac_device_info *hw)
}
static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
- u16 perfect_match, bool is_double)
+ bool is_double)
{
void __iomem *ioaddr = hw->pcsr;
@@ -279,29 +265,6 @@ static void dwxgmac2_update_vlan_hash(struct mac_device_info *hw, u32 hash,
value &= ~VLAN_VID;
writel(value, ioaddr + VLAN_TAG);
- } else if (perfect_match) {
- u32 value = readl(ioaddr + XGMAC_PACKET_FILTER);
-
- value |= XGMAC_FILTER_VTFE;
-
- writel(value, ioaddr + XGMAC_PACKET_FILTER);
-
- value = readl(ioaddr + VLAN_TAG);
-
- value &= ~VLAN_VTHM;
- value |= VLAN_ETV;
- if (is_double) {
- value |= VLAN_EDVLP;
- value |= VLAN_ESVL;
- value |= VLAN_DOVLTC;
- } else {
- value &= ~VLAN_EDVLP;
- value &= ~VLAN_ESVL;
- value &= ~VLAN_DOVLTC;
- }
-
- value &= ~VLAN_VID;
- writel(value | perfect_match, ioaddr + VLAN_TAG);
} else {
u32 value = readl(ioaddr + XGMAC_PACKET_FILTER);
--
2.34.1