we have a custom board-design for the Xavier NX, Xavier TX2 NX, Nano. For the Nano and Xavier NX the board works without any problem regarding the Shutdown_req* Pin (Power down sequencing). But the TX2 NX won’t shutdown completely. The last message we receive via UART Debug is “reboot: Power down”.
After that the Jetson SOM should pull the PIN 233 (SHUTDOWN_REQ*) from high to low. But this didn’t happen. We’ve tested it with a custom DTB and with the original Lanai DTB and have the same issues.
Attached there is the dmesg output from the original Lanai DTB and also the GPIO relevant outputs (unlike the Nano or Xavier NX, there a way fewer GPIOs in this output).
Finally i found the issue, the blogposts later in this text helped me alot. I think this issue is fixed in Jetson Linux Version 32.7.3, we’ve used 32.7.2. Below the solution description for others in the same situation.
The file “tegra186-bpmp-p3636-0001-a00-00.dtb” contains the shutdown-sequence issue. The file could be found in Linux_for_Tegra/bootloader/t186ref. It’s necessary to decompile the file using dtc. Afterwards you need to change the shutdown-sequence to this shutdown-sequence = [fc 00 3c ff 07 d0 3c 2f 00 3c 3d 00]; (like it’s shown in the issue patch here: Shut-down request pin issue onJetson TX2-NX (4.6.1) - #12 by WayneWWW). After that compile it again and change the file in the Linux for Tegra folder again.