From:   Steen Hegelund <steen.hegelund@microchip.com>
To:     "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
CC:     Steen Hegelund <steen.hegelund@microchip.com>,
        <UNGLinuxDriver@microchip.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        "Casper Andersson" <casper.casan@gmail.com>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Wan Jiabing <wanjiabing@vivo.com>,
        "Nathan Huckleberry" <nhuck@google.com>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        "Steen Hegelund" <Steen.Hegelund@microchip.com>,
        Daniel Machon <daniel.machon@microchip.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        Lars Povlsen <lars.povlsen@microchip.com>,
        Dan Carpenter <error27@gmail.com>,
        Michael Walle <michael@walle.cc>
Subject: [PATCH net-next v2 05/10] net: microchip: sparx5: Improve the error handling for linked rules
Date:   Tue, 14 Feb 2023 11:40:44 +0100
Message-ID: <20230214104049.1553059-6-steen.hegelund@microchip.com>
In-Reply-To: <20230214104049.1553059-1-steen.hegelund@microchip.com>
References: <20230214104049.1553059-1-steen.hegelund@microchip.com>
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Ensure that an error is returned if the VCAP instance was not found.
The chain offset (diff) is allowed to be zero as this just means that the
user did not request rules to be linked.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
---
 drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c b/drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c
index d73668dcc6b6..82d5138f149e 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c
@@ -551,12 +551,16 @@ static int sparx5_tc_add_rule_link(struct vcap_control *vctrl,
 	struct vcap_admin *to_admin = vcap_find_admin(vctrl, to_cid);
 	int diff, err = 0;
 
-	diff = vcap_chain_offset(vctrl, from_cid, to_cid);
-	if (!(to_admin && diff > 0)) {
+	if (!to_admin) {
 		pr_err("%s:%d: unsupported chain direction: %d\n",
 		       __func__, __LINE__, to_cid);
 		return -EINVAL;
 	}
+
+	diff = vcap_chain_offset(vctrl, from_cid, to_cid);
+	if (!diff)
+		return 0;
+
 	if (admin->vtype == VCAP_TYPE_IS0 &&
 	    to_admin->vtype == VCAP_TYPE_IS0) {
 		/* Between IS0 instances the G_IDX value is used */
-- 
2.39.1