The ISO 11783-5 standard, in "4.5.2 - Address claim requirements", states:
d) No CF shall begin, or resume, transmission on the network until 250
ms after it has successfully claimed an address except when
responding to a request for address-claimed.
But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
prioritization" show that the CF begins the transmission after 250 ms
from the first AC (address-claimed) message even if it sends another AC
message during that time window to resolve the address contention with
another CF.
As stated in "4.4.2.3 - Address-claimed message":
In order to successfully claim an address, the CF sending an address
claimed message shall not receive a contending claim from another CF
for at least 250 ms.
As stated in "4.4.3.2 - NAME management (NM) message":
1) A commanding CF can
d) request that a CF with a specified NAME transmit the address-
claimed message with its current NAME.
2) A target CF shall
d) send an address-claimed message in response to a request for a
matching NAME
Taking the above arguments into account, the 250 ms wait is requested
only during network initialization.
Do not restart the timer on AC message if both the NAME and the address
match and so if the address has already been claimed (timer has expired)
or the AC message has been sent to resolve the contention with another
CF (timer is still running).
Signed-off-by: Devid Antonio Filoni <devid.filoni@egluetechnologies.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20221125170418.34575-1-devid.filoni@egluetechnologies.com
Fixes: 9d71dd0c70 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
4ae5e1e97c