Re: [PATCH 4/4] can: flexcan: Disable error irq when in error passive

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

[-- Attachment #1: Type: text/plain, Size: 1172 bytes --]

On 08/12/2014 03:43 PM, Alexander Stein wrote:
> If the error irq is enabled and the hardware is trying to send a CAN
> message to an open bus it will receive a lot of acknowledge errors and
> generating lots of interrupts. So error interrupts are disabled when
> entering error passive and reenable them when leaving error passive.
> We can only leave error passive by receiving CAN frames in which case NAPI
> is scheduled anyway or by sending more CAN frames when send is possible
> again. But with the transition of error counters from 96 to 95 the flags
> TX_WRN and RX_WRN are gone again, so we need to remember the flags state
> to detect a change there.

There are use cases where the error interrupts even when in passive mode
are essential. You have a use case, where you'd like to turn them off
completely. Have you had a look at the bus error limiting patches?

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: 181 bytes --]