Re: SocketCAN stops read after RX overflow, is it normal?

[Marc Kleine-Budde <mkl@pengutronix.de>]

[-- Attachment #1: Type: text/plain, Size: 1496 bytes --]

On 09/02/2015 12:17 PM, Guillaume Picquet wrote:
> Hi every one.
> 
> I’m not sure to post to the correct list, if so please correct me.

100% correct.

> I’m doing tests on embedded hardware with integrated CAN bus interface 
> (based on AT91). The driver provides Linux Socket API and I try to see 
> the limits:
> I have one transmitter that writes CAN frames (CAN_RAW) as fast as 
> possible and a receiver that reads continuously.
> After a moment the receiver gets an error frame signalling RX overflow. 
> I have no problem with that, it's normal and expected.
> But question is why at this point no more frame is received ?

It's probably a bug in the driver.

> read() do not return, I've tested also with select() which return timeout.
> (The restart-ms option is set)
> 
> I expected some dropped frames and others RX buffer errors but not the 
> end of reception.
> 
> The only way to recover the interface is to set it down and up again.

Try the patches I send you in the other mail. They switch the at91 to
the new infrastructure. Some generic testing show good results, but it
seems you have a harder/better test case.

Hope that helps, please keep us informed,
Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 455 bytes --]