Very Strange suspend/wake uart console behaviour.

Hi All,

I’m seeing something very strange with my tx2 on my dev board. When I put it to sleep using a ssh connection over ethernet, the uart console tttS0 is enabled, it wakes up ok using the rtc as a wake source.

When I disable the uart console however, & put it to sleep in the exact same way, it looks like the Tx2 wakes up but it no longer connects to the ethernet, no lights on the connector or the hub. The only signs of life are the other leds on the board, chiefly the green led by the “SOC” button.

Is there something to do with the tx2 wake process that relies on the debug console enabled on uart?

hello hannaBarbera,

may I have more details about how you disable the UART console. did you have kernel modification to disable that?
besides, may I know which JetPack release you’re working with.
thanks

I edit the cboot args so “console=ttyS0,115200” doesn’t appear as part of my system.img. Then whenever I want the console on or off I add/remove that string to /boot/extlinux/elinux.conf.

Will update jetpack version later.

Jetpack version is 4.2.2

Hi hannaBarbera,

What’s suspend command are you using?
Please try below pipeline:

$ sudo systemctl suspend

Yup! That the command I use.

Another UART/suspend issue.

I’m using the UART coming from D5/D8. I’ve editing the bpmp dtb so console=0xff as opposed to the original console=7. Whenever /dev/ttyTHS6 is open and the system is suspended, the whole System seems to crash! No further entries in syslog etc. So it doesn’t look like it goes into suspend & never wakes.

Any ideas? I know that port is SPE debug, is it possible there’s an internal quirk of the TX2?