topic Re: IMX8MP: CAN FD can't leave self loopback mode in i.MX Processors

IMX8MP: CAN FD can't leave self loopback mode

yoooh8668 — Mon, 28 Nov 2022 02:40:37 GMT

Hi,

I use imx8mp to run the loopback test, but seems like it can't leave the self loopback mode.

Here is the test script:

#!/bin/bash COUNT=1 while true do echo -e "\n count=$COUNT\n" COUNT=$(($COUNT+1)) echo -e "\n##test 1 wire-loopback" ip link set can0 up type can bitrate 500000 dbitrate 2000000 fd on ip link set can1 up type can bitrate 500000 dbitrate 2000000 fd on candump can1 & candump can0 & cansend can0 123##1 cansend can1 123##1 sleep 2 echo -e "# kill all candump and set can to down" killall candump ip link set can0 down ip link set can1 down echo -e "\n##test2 self-loopback" ip link set can0 up type can bitrate 500000 dbitrate 2000000 fd on loopback on ip link set can1 up type can bitrate 500000 dbitrate 2000000 fd on loopback on candump can1 & candump can0 & cansend can0 123##1 cansend can1 123##1 sleep 2 echo -e "# kill all candump and set can to down" killall candump ip link set can0 down ip link set can1 down echo -e "\n##test 3-1 wire-loopback can0-> can1" ip link set can0 up type can bitrate 500000 dbitrate 2000000 fd on ip link set can1 up type can bitrate 500000 dbitrate 2000000 fd on candump can1 & cansend can0 123##1 sleep 2 echo -e "# kill all candump and set can to down" killall candump ip link set can0 down ip link set can1 down echo -e "\n##test 3-2 wire-loopback can1->can0" ip link set can0 up type can bitrate 500000 dbitrate 2000000 fd on ip link set can1 up type can bitrate 500000 dbitrate 2000000 fd on candump can0 & cansend can1 123##1 sleep 2 echo -e "# kill all candump and set can to down" killall candump ip link set can0 down ip link set can1 down done

Here is the result:

root@edm-g-imx8mp:~# ./2_test_can.sh count=1 ##test 1 wire-loopback RTNETLINK answers: Device or resource busy RTNETLINK answers: Device or resource busy can0 123 [00] can0 123 [00] can1 123 [00] can1 123 [00] # kill all candump and set can to down ##test2 self-loopback [ 716.425196] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 716.435328] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready can0 123 [00] can0 123 [00] can1 123 [00] can1 123 [00] # kill all candump and set can to down ##test 3-1 wire-loopback can0-> can1 [ 718.468560] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 718.479017] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready # kill all candump and set can to down ##test 3-2 wire-loopback can1->can0 [ 720.511155] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 720.521521] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready # kill all candump and set can to down count=2 ##test 1 wire-loopback [ 722.553288] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 722.563775] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready can0 123 [00] can0 123 [00] can1 123 [00] can1 123 [00] # kill all candump and set can to down ##test2 self-loopback [ 724.597857] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 724.608352] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready can0 123 [00] can0 123 [00] can1 123 [00] can1 123 [00] # kill all candump and set can to down ##test 3-1 wire-loopback can0-> can1 [ 726.642325] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 726.652862] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready # kill all candump and set can to down ##test 3-2 wire-loopback can1->can0 [ 728.684203] IPv6: ADDRCONF(NETDEV_CHANGE): can0: link becomes ready [ 728.694695] IPv6: ADDRCONF(NETDEV_CHANGE): can1: link becomes ready

Re: IMX8MP: CAN FD can't leave self loopback mode

Dhruvit — Wed, 30 Nov 2022 12:48:05 GMT

Hi @yoooh8668,

I don't think this issue could be due to can't leaving self-loopback mode as CAN works again as " 1 wire-loopback" in the count 2 test.

To test CAN functionality in imx SoCs one can try looking at root/test/can/doc/FSL-UT-CAN-003.txt at imx-test.

I hope it helps!

Best regards,
Dhruvit.

Re: IMX8MP: CAN FD can't leave self loopback mode

yoooh8668 — Fri, 09 Dec 2022 08:01:22 GMT

But what makes it can not use single CAN communication in test 3-1 3-2?

We found with the 'loopback on' need to make the CAN listening too to transfer the data.

So we thing it might be the 'can't leave self-loopback mode'.

Or the 'loopback on' test is wrong with my script?

Besides, I don't see the 'loopback on' command in 'FSL-UT-CAN-003.txt '.

Re: IMX8MP: CAN FD can't leave self loopback mode

Dhruvit — Tue, 13 Dec 2022 09:09:27 GMT

Hi @yoooh8668,

Please provide me with the part number of the processor you are using.

Thanks & Regards,
Dhruvit.

Re: IMX8MP: CAN FD can't leave self loopback mode

yoooh8668 — Wed, 21 Dec 2022 10:38:03 GMT

Sorry for late reply.

it's PIMXL8DNVNL ZAB.

Re: IMX8MP: CAN FD can't leave self loopback mode

Dhruvit — Thu, 22 Dec 2022 08:34:45 GMT

Hi @yoooh8668,

Thank you for your reply.

PIMXL8DNVNLZAB is a consumer-grade SOC.

It should be mentioned that only industrial grade i.MX8MP Processors support CAN-FD.

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Thanks & Regards,
Dhruvit.

Re: IMX8MP: CAN FD can't leave self loopback mode

yoooh8668 — Fri, 30 Dec 2022 03:13:26 GMT

I got this part number from the web side, maybe it's wrong.

U-Boot 2021.04-AUTOINC+g9368a0d86d (Aug 03 2022 - 08:29:30 +0000) CPU: i.MX8MP[8] rev1.1 1600 MHz (running at 1200 MHz) CPU: Industrial temperature grade (-40C to 105C) at 49C Reset cause: POR Model: TechNexion EDM-G-IMX8MP DRAM: 8 GiB MMC: FSL_SDHC: 1, FSL_SDHC: 2

But the U-Boot say it's Industrial grade.