can problems on socfpga [was Re: [PATCH v2 4/6] ARM: socfpga: dts: add can0+1]

Pavel Machek pavel at
Sat Apr 26 13:31:31 PDT 2014

On Sat 2014-04-26 11:36:46, Pavel Machek wrote:
> Hi!
> > To get this working well, I had to install a few of the patches that
> > Benedict Spranger submitted ([PATCH 05/16] c_can: use 32 bit access for
> > D_CAN) on 9/9/2013.
> > 
> > I have the patches on our rocketboard branch
> > (;a=summary)
> > 
> > I planned to upstream these changes but there have been some major
> > changes to CAN recently that may require some refactoring.
> I ported those changes to 3.15-rc2 (but can't test them at the
> moment).

Ok, it seems it is possible to test CAN without actual can hardware
using loopback:

ip link set can0 up type can bitrate 125000 loopback on
ifconfig can0 up
candump can0 &
cansend can0 "123#DEADBEEF"

Moreover, it seems that previous two patches do the trick. Packets are
now echoed as expected. (Ok, small question is "why twice", but I
guess that's just CAN...?)

root at sockit:~# ip link set can0 up type can bitrate 125000 loopback on
c_can_platform ffc00000.d_can can0: setting BTR=1c31 BRPE=0000
root at sockit:~# ifconfig can0 up
root at sockit:~# candump can0 &
root at sockit:~# cansend can0 "123#DEADBEEF"
  can0  123   [4]  DE AD BE EF
  can0  123   [4]  DE AD BE EF
root at sockit:~# 

Best regards,

(cesky, pictures)

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