[PATCH iwl-net 06/10] ice: keep adding MAC filters after one that already exists

[Petr Oros <poros@redhat.com>]

ice_add_mac() returns as soon as one entry of the list fails, including
-EEXIST for a filter that is already programmed for the VSI. The rest of
the list is never added. ice_vsi_sync_fltr() treats -EEXIST as success,
so the skipped addresses are considered synced and their traffic is
dropped until they are removed and added again.

In a test that adds 50 multicast addresses to a port in a burst with
the port MAC address in the middle of it, 19 of them were left without
a filter.

Continue with the next entry on -EEXIST and report it once the whole
list has been processed. Other errors still stop the loop.

There is no i40e counterpart of this fix, i40e keeps its MAC filters in
a hash with a state per filter and syncs them differently. It was found
while building a reproducer for the MAC filter overflow handling that
i40e fixed in commit e58872398684 ("i40e: fix disabling overflow
promiscuous mode") and commit 7363115efb04 ("i40e: do not force filter
failure in overflow promiscuous").

Commit bbb968e8b34c ("ice: Fix issues updating VSI MAC filters") dealt
with the same problem for the VF MAC filter requests, which are now
added one by one with -EEXIST tolerated, but left ice_add_mac() and the
PF filter sync as they were.

Fixes: 89f3e4a5b762 ("ice: Do not bail out when filter already exists")
Assisted-by: LLM
Signed-off-by: Petr Oros <poros@redhat.com>
---
 drivers/net/ethernet/intel/ice/ice_switch.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_switch.c b/drivers/net/ethernet/intel/ice/ice_switch.c
index 2ee5cb6ffdab1f..239d4d9633baa6 100644
--- a/drivers/net/ethernet/intel/ice/ice_switch.c
+++ b/drivers/net/ethernet/intel/ice/ice_switch.c
@@ -3659,7 +3659,9 @@ int ice_add_mac(struct ice_hw *hw, struct list_head *m_list)
 
 		m_list_itr->status = ice_add_rule_internal(hw, ICE_SW_LKUP_MAC,
 							   m_list_itr);
-		if (m_list_itr->status)
+		if (m_list_itr->status == -EEXIST)
+			status = -EEXIST;
+		else if (m_list_itr->status)
 			return m_list_itr->status;
 	}
 
-- 
2.55.0