Hi Wolfgang, On 21/06/18 10:30, Wolfgang Grandegger wrote: [...snip...] >>>> It's when the power is going on or off to the device. We have some >>>> contactors to some big power that probably introduces a fair amount of >>>> noise on connect/disconnect causing can errors. The device we are >>>> talking to gets power from the same circuit. Though it's fine once up, >>>> it is born and dies in a hell fire of noise. But CAN should be ok with that. >>> So you have a bus error storm when the device is switched on (and off). >>> I suspect that the problem is while initializing the CAN device. >>> >>> [...snip...] >> The device is designed for this harsh environment (not by us), though it >> too is still in development. >> CAN should be pretty fault tolerant and it's the c_can/d_can driver that >> has the issue. It's out of sync with it's chip's status. >> When I get time on the setup, I'll see if that interrupt change stops >> that happening. > I didn't say that it's your fault ;). I just want to understand what > could cause the problem! I don't think it's hardware, either. Hopefully I've now loaded you with the situation. It's fairly rare to happen even in our unusually harsh environment, unless we really push it with unrealistically tight loop, so this definitely comes under crazy edge cases. ;-) I'm just waiting for my turn to try my interrupt idea on the hardware (I hogged it yesterday) and reading the datasheet. Even if that works, I'm still thinking it might be an idea to check for bus off in the send as a fall back with a "this should never happen" kind of warning. > Wolfgang. Joe -- To unsubscribe from this list: send the line "unsubscribe linux-can" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
