[PATCH iwl-net 5/5] iavf: return 0 when TC flower filter not found after qdisc teardown

[Aleksandr Loktionov <aleksandr.loktionov@intel.com>]

From: Kiran Patil <kiran.patil@intel.com>

When an egress qdisc is destroyed, the driver proactively deletes all
associated cloud filters to prevent stale hardware state, decrementing
num_cloud_filters to zero in the process.

The kernel netdev layer is unaware of this implicit cleanup and may
still try to delete the same filters individually. If the filter is
not found in the driver's list and num_cloud_filters is already zero,
return 0 instead of -EINVAL to avoid confusing upper layers that
believe the filter is still offloaded in hardware.

Fixes: 0075fa0fadd0 ("i40evf: Add support to apply cloud filters")
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_main.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 5e4035b..05aaae9 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -4175,7 +4175,16 @@ static int iavf_delete_clsflower(struct iavf_adapter *adapter,
 	if (filter) {
 		filter->del = true;
 		adapter->aq_required |= IAVF_FLAG_AQ_DEL_CLOUD_FILTER;
-	} else {
+	} else if (adapter->num_cloud_filters) {
+		/* When the egress qdisc is detached the driver implicitly
+		 * deletes all associated cloud filters to prevent stale
+		 * hardware entries, reducing num_cloud_filters to zero.
+		 * The netdev layer is unaware of this implicit cleanup and
+		 * may still request deletion of individual filters.  Only
+		 * return -EINVAL when a filter lookup fails and
+		 * num_cloud_filters is non-zero, indicating a genuine
+		 * lookup failure rather than a post-teardown stale delete.
+		 */
 		err = -EINVAL;
 	}
 	spin_unlock_bh(&adapter->cloud_filter_list_lock);
-- 
2.52.0