Re: Bus off

[Wolfgang Grandegger <wg@grandegger.com>]

On 06/27/2014 05:45 PM, Jason R1 White wrote:
> So is it still the recommendation to close the interface to flush the 
> queues?

As I said: the purpose of "restart" is not to do a fast if down->up.

> Is there anything planned for an ip command or IOCTL to do this?

It's on the wish list, let's say. Somebody needs to implement it. It's
also not straight-forward because there might be more than one socket
sending out CAN messages. For standard network devices there is no way
to flush all TX queues, IIRC.

Wolfgang.

>> On 06/27/2014 05:22 PM, Jason R1 White wrote:
>>>>
>>>> On Thu, Jun 26, 2014 at 10:13:17AM -0700, Austin Schuh wrote:
>>>>> Does anyone know if the TX queues are cleared on BUS-OFF?
>>>>
>>>> No queues are emptied, you will only loose the curent pending 
>>> transmission.
>>>>
>>>>>
>>>
>>> I thought the restart mechanism flushed the transmit queues (ip link 
> set 
>>> can0 type can restart).  Is this not the case?  That is what we are 
>>> relying upon.  We used to close and open the interface explicitly. 
>>
>>
>> "restart" and "restart-ms" should trigger a bus-off recovery:
>>
>>
> http://lxr.free-electrons.com/source/Documentation/networking/can.txt#L1087
> 
>>
>>>
>>> For controls its not a good practice to let stale data sit in the 
> output 
>>> buffer. 
>>
>> The intention of restart(-ms) was to simply trigger a bus-off recovery.
>> The name is not well chosen, though.
>>
>> Wolfgang.
> 
>