Re: [PATCH] can: at91_can: fix passive-state AERR flooding

On 05.10.2021 13:30:23, Brandon Maier wrote:

When the at91_can is a single node on the bus and a user attempts to
transmit, the can state machine will report ack errors and increment the
transmit error count until it reaches the passive-state. Per the
specification, it will then transmit with a passive error, but will stop
incrementing the transmit error count. This results in the host machine
being flooded with the AERR interrupt forever, or until another node
rejoins the bus.

To prevent the AERR flooding, disable the AERR interrupt when we are in
passive mode.

Can you implement Bus Error Reporting?

| https://elixir.bootlin.com/linux/v5.14/source/include/uapi/linux/can/netlink.h#L99

This way the user can control if bus errors, and the ACK error is one of
them, should be reported. Bus error reporting is disabled by default. I
think enabling AT91_IRQ_ERR_FRAME only if CAN_CTRLMODE_BERR_REPORTING is
active should do the trick.

regards,
Marc

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