Re: C_CAN: can frame drops

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

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On 07/25/2014 10:13 AM, Ssagarr Patil wrote:
>>> I am using the c_can driver for latest kernel and using the latest canutils to dump to a file.
>>> My can bus is set at a rate of 1Mb (receiving 7000fps bus load of 80%).
>>>
>>> When I use the candump tool to dump can frames I get following message,
>>>
>>> 'DROPCOUNT: dropped 2223 CAN frames on 'any' socket (total drops 1629092)'
>>
>> These are the CAN frames dropped by the socket, this means as Oliver
>> pointed out, that the candump fails to read the CAN frames fast enough
>> from the socket. How do you connect to the linux box with the c_can?
>> Where are the CAN frames printed to?
>>
> Agreed this is dropped by the socket, so for this to solve I increased the socket size
> (with -r option of candump to 111173056) after doing this I see that there is frame drop in
> the driver ie I see this function c_can_handle_lost_msg_obj() being called frequently in which
> can frame is overwritten.
> 
> I have a can frame generator which I have connected to the EVM, the EVM is recieving the
> frames and just dumping it on stdout going ahead I need to log the canframes to SD card.

...and where is your stdout going? serial line, telnet, ssh?

Marc

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