On 06/12/2015 11:29 AM, Holger Schurig wrote:
> Hi people,
> 
> I have two i.MX6 based boards with built-in FLEXCAN. On both boards I
> loaded can_raw.
> 
> When I now run "cangen can0 -g 0 -x" one one board, I get frame errors
> on the others (no matter if I run candump on the receiving side).
> 
> 
> root@left:~# ifconfig can0; ip -s link show can0
> can0      Link encap:UNSPEC  HWaddr
> 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
>           UP RUNNING NOARP  MTU:16  Metric:1
>           RX packets:20249437 errors:6 dropped:0 overruns:0 frame:6
>           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:10
>           RX bytes:116445504 (111.0 MiB)  TX bytes:0 (0.0 B)
>           Interrupt:142
> 
> 3: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state
> UNKNOWN mode DEFAULT group default qlen 10
>     link/can
>     RX: bytes  packets  errors  dropped overrun mcast
>     116445504  20249437 6       0       6       0

These are probably RX-FIFO overrun errors:

>         /* FIFO overflow */                                                      
>         if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {                       
>                 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);    
>                 dev->stats.rx_over_errors++;                                     
>                 dev->stats.rx_errors++;                                          
>         }                                                                        

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   |