AM625: Linux CAN test error passive

Biao Li

Part Number: AM625

Tool/software:

Hi Expert,

customer is working on sdk9.2.

can you help look into below error from customer? I think this may regarding to the CAN sampling config, but I don't know how to change this in linux device tree.

I refer to below thread, can you help give some suggestion?

(+) PROCESSOR-SDK-AM62X: MCAN CCS test in Bare metal code - Processors forum - Processors - TI E2E support forums

BRP: 7+1 = 8
TSeg1: 5+1 = 6
TSeg2: 2+1 = 3

BR,

Biao

over 1 year ago

0 Kevin Peng over 1 year ago

TI__Expert 4308 points

Hi TI Experts,

We have help customer check the Linux CAN algorithm shown below. Customer has used AM335x many years before, they have compared the Linux CAN algorithm between AM335x & the current AM62x, and found there is no difference. However, they already SOP AM335x many years, not having this CAN error passive problem.

Could you help provide some suggestions to us?

Many Thanks,

Kevin

0 Aparna Patra over 1 year ago in reply to Kevin Peng

TI__Genius 12980 points

Hi Kevin,

If you want to change the MCAN bit timing parameters, you can modify it via command line, before starting MCAN communication.

$ ip link set canX type can tq 125 prop-seg 6 \
                            phase-seg1 7 phase-seg2 2 sjw 1
                            
$ ip link set canX type can bitrate 125000

Make sure necessary config options are enabled as mentioned below:

https://docs.kernel.org/networking/can.html#setting-the-can-bit-timing

Regards,
Aparna

0 Kevin Peng over 1 year ago in reply to Aparna Patra

TI__Expert 4308 points

Hi Aparna,

Thanks for your support!

By following the above method, customer solves the problem.

Now they are obtaining the baud rate by directly configuring the tq, seg and other values. (Previously if they directly configure the baud rate, it will mismatch with the time quanta & seg).

Thanks,

Kevin