Re: [PATCH V5 1/1] can: Add support for esd CAN PCIe/402 card

["Ahmed S. Darwish" <darwish.07@gmail.com>]

Hi Thomas,

On Tue, Mar 17, 2015 at 07:30:02AM +0100, Thomas Körper wrote:
> Hi Andri,
> 
> I've looked at the sources you mentioned, but I'm a little bit unsure now /
> the handling seems not perfectly consistent to me. (flexcan calls
> can_change_state() with tx/rx_state of 0 in the bus off path.
>

There're discrpeancies indeed on the BUSOFF path:

1) flexcan calls can_change_state(dev, cf, 0, 0). kvaser and others
   do can_change_state(dev, cf, tx, rx) where either tx or rx =
   CAN_STATE_BUS_OFF. In this case, kvaser and the other drivers
   are the _correct_ behavior. This is validated by can-dev
   can_chage_state() code:

	if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
		cf->can_id |= CAN_ERR_BUSOFF;
		return;
	}

2) flexcan calls can_bus_off(dev), while kvaser goes a layer deeper
   and directly calls netif_carrier_off(netdev). In this case,
   flexcan is the more correct behavior.


Thanks,
Darwish