[PATCH 5.4 094/134] net: xilinx: axienet: Fix dangling multicast addresses

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

5.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sean Anderson <sean.anderson@xxxxxxxxx>

[ Upstream commit 797a68c9de0f5a5447baf4bd3bb9c10a3993435b ]

If a multicast address is removed but there are still some multicast
addresses, that address would remain programmed into the frame filter.
Fix this by explicitly setting the enable bit for each filter.

Fixes: 8a3b7a252dca ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver")
Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Link: https://patch.msgid.link/20240822154059.1066595-3-sean.anderson@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/xilinx/xilinx_axienet.h  |  1 +
 .../net/ethernet/xilinx/xilinx_axienet_main.c | 21 ++++++++-----------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h
index bf1a19a00adc6..c43d437f22bdf 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -169,6 +169,7 @@
 #define XAE_UAW0_OFFSET		0x00000700 /* Unicast address word 0 */
 #define XAE_UAW1_OFFSET		0x00000704 /* Unicast address word 1 */
 #define XAE_FMI_OFFSET		0x00000708 /* Frame Filter Control */
+#define XAE_FFE_OFFSET		0x0000070C /* Frame Filter Enable */
 #define XAE_AF0_OFFSET		0x00000710 /* Address Filter 0 */
 #define XAE_AF1_OFFSET		0x00000714 /* Address Filter 1 */
 
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index 80bb6b85bd441..2aacc077ee2bc 100644
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -409,7 +409,7 @@ static int netdev_set_mac_address(struct net_device *ndev, void *p)
  */
 static void axienet_set_multicast_list(struct net_device *ndev)
 {
-	int i;
+	int i = 0;
 	u32 reg, af0reg, af1reg;
 	struct axienet_local *lp = netdev_priv(ndev);
 
@@ -431,7 +431,6 @@ static void axienet_set_multicast_list(struct net_device *ndev)
 		reg &= ~XAE_FMI_PM_MASK;
 		axienet_iow(lp, XAE_FMI_OFFSET, reg);
 
-		i = 0;
 		netdev_for_each_mc_addr(ha, ndev) {
 			if (i >= XAE_MULTICAST_CAM_TABLE_NUM)
 				break;
@@ -450,6 +449,7 @@ static void axienet_set_multicast_list(struct net_device *ndev)
 			axienet_iow(lp, XAE_FMI_OFFSET, reg);
 			axienet_iow(lp, XAE_AF0_OFFSET, af0reg);
 			axienet_iow(lp, XAE_AF1_OFFSET, af1reg);
+			axienet_iow(lp, XAE_FFE_OFFSET, 1);
 			i++;
 		}
 	} else {
@@ -457,18 +457,15 @@ static void axienet_set_multicast_list(struct net_device *ndev)
 		reg &= ~XAE_FMI_PM_MASK;
 
 		axienet_iow(lp, XAE_FMI_OFFSET, reg);
-
-		for (i = 0; i < XAE_MULTICAST_CAM_TABLE_NUM; i++) {
-			reg = axienet_ior(lp, XAE_FMI_OFFSET) & 0xFFFFFF00;
-			reg |= i;
-
-			axienet_iow(lp, XAE_FMI_OFFSET, reg);
-			axienet_iow(lp, XAE_AF0_OFFSET, 0);
-			axienet_iow(lp, XAE_AF1_OFFSET, 0);
-		}
-
 		dev_info(&ndev->dev, "Promiscuous mode disabled.\n");
 	}
+
+	for (; i < XAE_MULTICAST_CAM_TABLE_NUM; i++) {
+		reg = axienet_ior(lp, XAE_FMI_OFFSET) & 0xFFFFFF00;
+		reg |= i;
+		axienet_iow(lp, XAE_FMI_OFFSET, reg);
+		axienet_iow(lp, XAE_FFE_OFFSET, 0);
+	}
 }
 
 /**
-- 
2.43.0