Hi, On Mon, May 09, 2022 at 09:04:06PM +0200, Kurt Van Dijck wrote: > On ma, 09 mei 2022 19:03:03 +0200, Devid Antonio Filoni wrote: > > This is not explicitly stated in SAE J1939-21 and some tools used for > > ISO-11783 certification do not expect this wait. It will be interesting to know which certification tool do not expect it and what explanation is used if it fails? > IMHO, the current behaviour is not explicitely stated, but nor is the opposite. > And if I'm not mistaken, this introduces a 250msec delay. > > 1. If you want to avoid the 250msec gap, you should avoid to contest the same address. > > 2. It's a balance between predictability and flexibility, but if you try to accomplish both, > as your patch suggests, there is slight time-window until the current owner responds, > in which it may be confusing which node has the address. It depends on how much history > you have collected on the bus. > > I'm sure that this problem decreases with increasing processing power on the nodes, > but bigger internal queues also increase this window. > > It would certainly help if you describe how the current implementation fails. > > Would decreasing the dead time to 50msec help in such case. > > Kind regards, > Kurt > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
