[PATCH net v2 1/6] net: stmmac: Remove VLAN perfect matching dead code

[Ovidiu Panait <ovidiu.panait.rb@renesas.com>]

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@renesas.com>
---
v2 changes: None.

 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 b2b7d0242dd3..16fe56a1f617 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -6809,29 +6809,18 @@ 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