[PATCH RESEND] can: j1939: do not wait 250ms if the same addr was already claimed

From: Devid Antonio Filoni <devid.filoni@egluetechnologies.com>
To: Robin van der Gracht <robin@protonic.nl>,
	Oleksij Rempel <o.rempel@pengutronix.de>
Cc: kernel@pengutronix.de, linux-can@vger.kernel.org,
	Oleksij Rempel <linux@rempel-privat.de>,
	Oliver Hartkopp <socketcan@hartkopp.net>,
	Marc Kleine-Budde <mkl@pengutronix.de>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Maxime Jayat <maxime.jayat@mobile-devices.fr>,
	kbuild test robot <lkp@intel.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Devid Antonio Filoni <devid.filoni@egluetechnologies.com>
Subject: [PATCH RESEND] can: j1939: do not wait 250ms if the same addr was already claimed
Date: Mon,  9 May 2022 19:03:03 +0200	[thread overview]
Message-ID: <20220509170303.29370-1-devid.filoni@egluetechnologies.com> (raw)

This is not explicitly stated in SAE J1939-21 and some tools used for
ISO-11783 certification do not expect this wait.

Fixes: 9d71dd0 ("can: add support of SAE J1939 protocol")
Signed-off-by: Devid Antonio Filoni <devid.filoni@egluetechnologies.com>
---
 net/can/j1939/address-claim.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/can/j1939/address-claim.c b/net/can/j1939/address-claim.c
index f33c47327927..1d070c08edf1 100644
--- a/net/can/j1939/address-claim.c
+++ b/net/can/j1939/address-claim.c
@@ -165,6 +165,12 @@ static void j1939_ac_process(struct j1939_priv *priv, struct sk_buff *skb)
 	 * leaving this function.
 	 */
 	ecu = j1939_ecu_get_by_name_locked(priv, name);
+
+	if (ecu && ecu->addr == skcb->addr.sa) {
+		/* the address was already claimed with the same name, nothing to do */
+		goto out_ecu_put;
+	}
+
 	if (!ecu && j1939_address_is_unicast(skcb->addr.sa))
 		ecu = j1939_ecu_create_locked(priv, name);
 
-- 
2.25.1

