[PATCH v2] common/mlx5: fix mac deletion on Linux

[David Marchand]

Re-enable debug logs unconditionally, this helps understanding why mac
deletions were silently failing (while a bridge fdb del command was
working fine).

testpmd> mac_addr add 0 FA:35:44:3F:58:31
testpmd> mac_addr remove 0 FA:35:44:3F:58:31
mlx5_common: Interface 35 cannot remove MAC address FA:35:44:3F:58:31
	Operation not supported

Then, fix mac deletion as the NLM_F_CREATE == 0x200 flag is relevant
with a RTM_NEWNEIGH op.

Since kernel v5.19 though, for a RTM_DELNEIGH op, 0x200 == NLM_F_BULK
and passing this flag makes the deletion fail miserably for a single mac.

Fixes: ccdcba53a3f4 ("net/mlx5: use Netlink to add/remove MAC addresses")
Cc: stable at dpdk.org

Signed-off-by: David Marchand <david.marchand at redhat.com>
---
Changes since v1:
- fixed ternary usage... (thanks Dariusz),
- updated commitlog with a mention of Linux version when it got broken,

---
 drivers/common/mlx5/linux/mlx5_nl.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/common/mlx5/linux/mlx5_nl.c b/drivers/common/mlx5/linux/mlx5_nl.c
index eceb3d796f..8b19838a7e 100644
--- a/drivers/common/mlx5/linux/mlx5_nl.c
+++ b/drivers/common/mlx5/linux/mlx5_nl.c
@@ -581,8 +581,8 @@ mlx5_nl_mac_addr_modify(int nlsk_fd, unsigned int iface_idx,
 	} req = {
 		.hdr = {
 			.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
-			.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE |
-				NLM_F_EXCL | NLM_F_ACK,
+			.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK |
+				(add ? NLM_F_CREATE | NLM_F_EXCL : 0),
 			.nlmsg_type = add ? RTM_NEWNEIGH : RTM_DELNEIGH,
 		},
 		.ndm = {
@@ -612,7 +612,6 @@ mlx5_nl_mac_addr_modify(int nlsk_fd, unsigned int iface_idx,
 		goto error;
 	return 0;
 error:
-#ifdef RTE_PMD_MLX5_DEBUG
 	{
 		char m[RTE_ETHER_ADDR_FMT_SIZE];
 
@@ -622,7 +621,6 @@ mlx5_nl_mac_addr_modify(int nlsk_fd, unsigned int iface_idx,
 			iface_idx,
 			add ? "add" : "remove", m, strerror(rte_errno));
 	}
-#endif
 	return -rte_errno;
 }
 
-- 
2.53.0