Can bus cann't work normally on sabresd platform

[tangyuan]

HI

    I am debugging can bus on sabresd platform.But CAN bus cann't work normally on sabresd platform.

   I cann't probe the waveform from the CAN0_TX.

  Firstly i add the pin in board_mx6q_sabresd.h:

   MX6Q_PAD_GPIO_7__CAN1_TXCAN,
   MX6Q_PAD_GPIO_8__CAN1_RXCAN,

  Secondly ,I follow the steps below

   dmesg | grep can

    ip link set can0 up type can bitrate 125000

      ifconfig can0 up

      ifconfig can0

      cansend can0 -i0x100 11 22 33 44

     But i cann't still probe the waveform from the CAN0_TX

     The picture is as follows

    one 

   My kernel is linux 3.0.35. Attachment is my reference document

   Can you anyone help me ?

[tangyuan]

HI:

      igorpadykov:

      Do I need to connect CAN1_TX and CAN1_RX?

      Now ,i didn't connect CAN1_TX and CAN1_RX.But i get the data.

      My test command is as follws:

     root@freescale /$ ip link set can0 down
root@freescale /$ ip link set can0 type can bitrate 50000 loopback on
root@freescale /$ ip link set can0 up
flexcan imx6q-flexcan.0: writing ctrl=0x27293005
root@freescale /$ candump can0 &
[1] 2570
interface = can0, family = 29, type = 3, proto = 1

root@freescale /$ cansend can0 -i 0x01 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88
interface = can0, family = 29, type = 3, proto = 1
<0x001> [8] 11 22 33 44 55 66 77 88
root@freescale /$ 

root@freescale /$ cantest can0 1F334455#1122334455667788
root@freescale /$ <0x1f334455> [8] 11 22 33 44 55 66 77 88

 This is correct?

[igorpadykov]

>    Now ,i didn't connect CAN1_TX and CAN1_RX.But i get the data.

CAN1_RX should be connected to CAN1_TX in loopback mode

or other board, otherwise CAN1_RX may be treated by driver as always busy

state and will not send data.

[tangyuan]

HI:

        igorpadykov

        I have already connected CAN1_TX and CAN1_RX.

        I test as follows:

        s 

        Is this correct?

        I havn't  still probed  any waveform on CAN1_TX or CAN1_RX 

[tangyuan]

HI:

   igorpadykov:

•    The loopback test is that CAN1_TX connected CAN1_RX?

 

[igorpadykov]

yes

[igorpadykov]

Hi tang

for testing two boards should be used. Alternatively one can test

with imx-test package (..test/can folder)

www.nxp.com/lgfiles/NMG/MAD/YOCTO/imx-test-5.4.tar.gz

Best regards
igor
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[tangyuan]

HI:

   My main problem is that i cann't  probe any wareform from the CAN1_TX

[igorpadykov]

had you tried loopback test