MCIMX6ULL-EVK: UART1 and CAN interfaces

[pierluigi_p]

Dear NXP support team,

if I disable UART1 (the Linux console) of the demo images, CAN0 and CAN1 stop working with messages like

RTNETLINK answers: Connection timed out

I'm just changing the status property of uart1 node to "disabled" in the device tree.

I'm using NXP MCIMX6ULL-EVK and any official NXP image based on kernel 5.15.x or 6.1.x.

Could you please double-check on your side ?

Thanks

Best Regards

Pier

[joanxie]

how do you disable UART1?  disable in the dts file? if yes which detailed dts files do you change?

[pierluigi_p]

@joanxie, attached you can find the working imx6ull-14x14-evk.dtb (from latest official image with kernel 6.1.55_2.2.0) and imx6ull-14x14-evk-no-uart1.dtb (status="disabled"; in uart1 node of the device tree).

I've compiled the one without uart1 from the sources, but even if you decompile and compare them, the only difference is the status of uart1.

Please let me know if you need further details.

Thanks

BR

Pier

[joanxie]

pls give me imx6ull-14x14-evk-no-uart1.dts file, let me check what you detailed change

[pierluigi_p]

@joanxie, attached you can find both the original (working) and modified (not working) device tree sources.

As already reported, I've just disabled uart1, setting the status to "disabled".

Have you been able to double-check on your side ?

Thanks

Best Regards

Pier

[joanxie]

if you use imx6ull-14x14-evk.dts, can your CAN1 work? imx6ull-14x14-evk.dts works but imx6ull-14x14-evk-no-uart1.dts doesn't work? I got another customer who uses Variscite board, when they disable all of UARTs, they got CAN stuck, is it the same customer ? I will reproduce this on nxp board, but I don't think imx6ull evk board has this issue, after I reproduce, maybe I need you offer more detailed HW and SW information to double check

[pierluigi_p]

Hi @joanxie, CAN works fine without changes and stops working disabling uart1.

This is actually reported in my 1st message.

Again, have you been able to double-check on your side ?

Let me remind you that I'm already able to reproduce this behavior using NXP evaluation kit.

Thanks

Best Regards

Pier

[joanxie]

I will reproduce this on my side when I got the board, and I mailed to you, pls check it

[pierluigi_p]

Hi @joanxie, thanks for the update.

No mail received for the time being, but I'll keep waiting.

Best Regards

Pier