[PATCH net v2] net: ethernet: ti: am65-cpsw-nuss/cpsw-ale: Fix multicast entry handling in ALE table

[Chintan Vankar <c-vankar@ti.com>]

In the current implementation, flushing multicast entries in MAC mode
incorrectly deletes entries for all ports instead of only the target port,
disrupting multicast traffic on other ports. The cause is adding multicast
entries by setting only host port bit, and not setting the MAC port bits.

Fix this by setting the MAC port's bit in the port mask while adding the
multicast entry. Also fix the flush logic to preserve the host port bit
during removal of MAC port and free ALE entries when mask contains only
host port.

Fixes: 5c50a856d550 ("drivers: net: ethernet: cpsw: add multicast address to ALE table")
Signed-off-by: Chintan Vankar <c-vankar@ti.com>
---

This patch is based on commit 'd4f687fbbce4' of origin/main branch of
Linux net repo.

Link to v1:
https://lore.kernel.org/r/20260205070951.3170631-1-c-vankar@ti.com/

Changes from v1 to v2:
- Squashed two patches into one as a fix of the older implementation.
- Added "Fixes" tag in the commit.

 drivers/net/ethernet/ti/am65-cpsw-nuss.c | 2 +-
 drivers/net/ethernet/ti/cpsw_ale.c       | 9 ++++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 5924db6be3fe..967918050433 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -391,7 +391,7 @@ static void am65_cpsw_nuss_ndo_slave_set_rx_mode(struct net_device *ndev)
 	cpsw_ale_set_allmulti(common->ale,
 			      ndev->flags & IFF_ALLMULTI, port->port_id);
 
-	port_mask = ALE_PORT_HOST;
+	port_mask = BIT(port->port_id) | ALE_PORT_HOST;
 	/* Clear all mcast from ALE */
 	cpsw_ale_flush_multicast(common->ale, port_mask, -1);
 
diff --git a/drivers/net/ethernet/ti/cpsw_ale.c b/drivers/net/ethernet/ti/cpsw_ale.c
index bb969dd435b4..be7b69319221 100644
--- a/drivers/net/ethernet/ti/cpsw_ale.c
+++ b/drivers/net/ethernet/ti/cpsw_ale.c
@@ -450,14 +450,13 @@ static void cpsw_ale_flush_mcast(struct cpsw_ale *ale, u32 *ale_entry,
 				      ale->port_mask_bits);
 	if ((mask & port_mask) == 0)
 		return; /* ports dont intersect, not interested */
-	mask &= ~port_mask;
+	mask &= (~port_mask | ALE_PORT_HOST);
 
-	/* free if only remaining port is host port */
-	if (mask)
+	if (mask == 0x0 || mask == ALE_PORT_HOST)
+		cpsw_ale_set_entry_type(ale_entry, ALE_TYPE_FREE);
+	else
 		cpsw_ale_set_port_mask(ale_entry, mask,
 				       ale->port_mask_bits);
-	else
-		cpsw_ale_set_entry_type(ale_entry, ALE_TYPE_FREE);
 }
 
 int cpsw_ale_flush_multicast(struct cpsw_ale *ale, int port_mask, int vid)
-- 
2.34.1