Subject: [PATCH 09/33] mlxsw: spectrum_acl: Avoid warning after identical rules insertion

From: Jiri Pirko <[email-masked]>
Date: Wed, 29 May 2019 10:59:44 +0300

[ Upstream commit ef74422020aa8c224b00a927e3e47faac4d8fae3 ]

When identical rules are inserted, the latter one goes to C-TCAM. For
that, a second eRP with the same mask is created. These 2 eRPs by the
nature cannot be merged and also one cannot be parent of another.
Teach mlxsw_sp_acl_erp_delta_fill() about this possibility and handle it
gracefully.

Reported-by: Alex Kushnarov <[email-masked]>
Fixes: c22291f7cf45 ("mlxsw: spectrum: acl: Implement delta for ERP")
Signed-off-by: Jiri Pirko <[email-masked]>
Signed-off-by: Ido Schimmel <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 .../net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c    | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
index 2941967e1cc5..2e5ebcd01b4b 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
@@ -1169,13 +1169,12 @@ mlxsw_sp_acl_erp_delta_fill(const struct mlxsw_sp_acl_erp_key *parent_key,
 			return -EINVAL;
 	}
 	if (si == -1) {
-		/* The masks are the same, this cannot happen.
-		 * That means the caller is broken.
+		/* The masks are the same, this can happen in case eRPs with
+		 * the same mask were created in both A-TCAM and C-TCAM.
+		 * The only possible condition under which this can happen
+		 * is identical rule insertion. Delta is not possible here.
 		 */
-		WARN_ON(1);
-		*delta_start = 0;
-		*delta_mask = 0;
-		return 0;
+		return -EINVAL;
 	}
 	pmask = (unsigned char) parent_key->mask[__MASK_IDX(si)];
 	mask = (unsigned char) key->mask[__MASK_IDX(si)];
-- 
2.20.1