PROCESSOR-SDK-AM62A: Deep Sleep Support in falcon mode.

Tool/software:

Hi TI Experts,

I’m currently working on enabling Falcon boot mode on the SK-AM62A-LP platform using TI Linux SDK 9.2 along with the tisdk-edgeai-image. As part of my optimization efforts, I upgraded U-Boot from the SDK-default 2023.04 to 2024.04 to address the initial SD card / eMMC load speed issue, as discussed in this related thread:
SK-AM62A-LP: Load speed problem with eMMC in Falcon boot mode.

Since Falcon boot essentially skips only the A53 SPL stage, I expect the rest of the system functionalities, including power management and suspend/resume flows, to remain functionally consistent with normal boot.

Per TI's SDK 9.2 documentation and forum guidance, I’ve removed the C7x DSP remoteproc driver, which is required for enabling system suspend (deep sleep) on AM62A-class devices. Following this, I attempted to enter suspend using the following command:

root@am62axx-evm:/opt/edgeai-gst-apps# modprobe -rf ti_k3_dsp_remoteproc
root@am62axx-evm:/opt/edgeai-gst-apps# rtcwake -m mem -s 10
rtcwake: wakeup from "mem" using /dev/rtc0 at Thu Jan  1 00:01:35 1970

For wake-up, I configured the internal RTC as the wakeup source with a 10-second timeout. The system successfully enters suspend, but fails to wake up after the configured 10 seconds.

Interestingly, if I keep the board powered on after entering suspend, it spontaneously boots from start after 2–5 minutes, which is unexpected and inconsistent.

To rule out known issues, I also removed the OPTEE HWRNG driver, as recommended for GP devices in certain cases, but the behavior remains unchanged.

My Questions:

1. Are there known limitations with wakeup from deep sleep in Falcon boot mode?

2. Could this behavior be related to DM firmware or some other subsystem not initialized properly due to Falcon boot skipping the SPL stage?