AM62A3: Deep sleep is giving error in SDK 9.2

Hello Sathiya,

Graceful shutdown is not enabled on the remote core, so when Linux tries to shut down the remote core, it fails. After that, Linux aborts the low power transition.

For more information about graceful shutdown and enabling graceful shutdown on cores like the MCU R5F, refer to the AM62Ax academy, Multicore module, page Graceful Shutdown: https://dev.ti.com/tirex/explore/node?node=A__AQv-WbXTryBifCo43cs4Yw__AM62A-ACADEMY__WeZ9SsL__LATEST

1) What version of Linux SDK are you running?

2) What firmware binary is running on the C7?

Regards,

Nick

Hi Nick,

Nick Saulnier said:

1) What version of Linux SDK are you running?

SDK 9.2

Nick Saulnier said:

2) What firmware binary is running on the C7?

How to find this?

Hi Sathiya,

Just to note, there is workaround since the C7x doesn't support graceful shutdown by unloading the driver: modprobe -rf ti_k3_dsp_remoteproc

Then reload the driver after sleep: modprobe ti_k3_dsp_remoteproc

Thanks,

Anshu

Hi Anshu,

Whenever I tried removing kernel module, I got this error.

root@am62axx-evm:/sys/power# modprobe -rf ti_k3_dsp_remoteproc
[  102.562564] k3-dsp-rproc 7e000000.dsp: k3_dsp_rproc_stop: timedout waiting for rproc completion event
[  102.571857] remoteproc remoteproc0: can't stop rproc: -16
root@am62axx-evm:/sys/power# 

I did a workaround by disabling C7X in device tree. It worked. But it is not the solution.

tiovxisp from gstreamer needs the C7X I suppose. So, disabling C7X will disable ISP utilization eventually.

Hello Sathiya,

Interesting, so the modprobe workaround seems limited by the remoteproc driver's graceful shutdown requirements as well. That makes sense to me.

This is a hack - I am not sure if the C7 would continue working as expected after you booted it back up. Please try modifying the ti_k3_dsp_remoteproc driver like this: (and then rebuild kernel & kernel modules to apply the change):
drivers/remoteproc/ti_k3_dsp_remoteproc.c

    ret = wait_for_completion_timeout(&kproc->shut_comp, to);
    if (ret == 0) {
        dev_err(dev, "%s: timedout waiting for rproc completion event\n", __func__);
        dev_err(dev, "%s: shutting down DSP anyway\n", __func__);
            /*return -EBUSY;*/
    };

In the meantime, I will route this feedback back to the developers.

Regards,

Nick

Hi Nick,

Any update on this?

Hi,

Nick is out of office for another week and he will respond to your query once he returns.

Regards,
Krunal

Edited July 17 2024

Hello Sathiya,

We will NOT be able to prioritize adding graceful shutdown support for C7 and edgeAI applications running on the C7 for the SDK 10.0 release coming in the next month or so. This is not fully accurate as of today. Please see my next response for details: We are currently targeting adding that functionality for the SDK 10.1 release (currently scheduled for the end of 2024), but the developers have not yet started looking into it so I am not sure how much work will be involved.

The Linux remoteproc driver already supports graceful shutdown for C7. Enabling graceful shutdown in the Linux remoteproc driver for C7 should be relatively easy. I am not sure how easy it will be for the team to modify their C7 code to listen for and handle graceful shutdown requests.

Regards,

Nick

Can you give me some codes, places, drivers where I can look for to enable graceful shutdown of C7X on my own.

If I can be able to do it successfully, I will update in this thread.

Hello Sathiya,

Source code for enabling graceful shutdown on your own

From a Linux driver standpoint, no modifications are needed. The Linux driver already supports graceful shutdown:
drivers/remoteproc/ti_k3_dsp_remoteproc.c
commit a2313a78eb2e
remoteproc: k3-dsp: Introduce PM suspend/resume handlers

From a C7 firmware standpoint, the source code is in Firmware builder. Please refer to this page for how to request access:
https://software-dl.ti.com/processor-sdk-linux/esd/AM62AX/09_02_00/exports/edgeai-docs/common/sdk_components.html#firmware-builder

Please note that at this point in time, my team is unable to answer questions about the code in firmware builder (by contrast, we CAN answer questions about MCU+ SDK code). So this package is provided "as-is".

For guidance on the kind of MCU+ side code that is needed to implement graceful shutdown, please refer to the AM62Ax academy, multicore module, Graceful Shutdown page. Specifically, section "MCU+ code to enable graceful shutdown": https://dev.ti.com/tirex/explore/node?node=A__AQv-WbXTryBifCo43cs4Yw__AM62A-ACADEMY__WeZ9SsL__LATEST 

Timeframe for a TI solution

I need to amend my previous comment on timeframe for a TI implementation: we REQUESTED that graceful shutdown for the Edge AI software running on C7 would be added for SDK 10.1, but so far the dev team has NOT actually allocated resources for that effort. So it may or may not actually happen, and if it happens, it may or may not happen as soon as SDK 10.1. Future customers, if you are curious about the current status, feel free to create a new thread and ask for an update.

Regards,

Nick

Hello Sathiya,

Sounds good! Please feel free to reach out in the future on another thread.

Regards,

Nick