Jetson agx orin: Clarification on SOF/EOF Timestamps in Tegra Camera Module Debug Logs

Robotics & Edge Computing Jetson Systems Jetson AGX Orin
1

Hi NVIDIA Team,
SDK version: Jetson_Linux_R36.4.3_aarch64.tbz2
AGX ORIN 64GB DevKit
In the rtcpu_debug logs captured from our camera module, we observed SOF and EOF timestamps. Could you clarify:

Module Association: Which module’s data frame boundaries do SOF and EOF correspond to (e.g., VI, CSI, or DMA controller)?
DMA Timing Alignment: Are these timestamps synchronized with the actual DMA write operations?
Timestamp Baseline Mismatch: The SOF/EOF values (e.g., sof:939.145750496) and system timestamps (e.g., 874.999179) appear to use different time bases. How can we reconcile this discrepancy?
Example Log:

[16-28-44.900]  vi-output, lh_a-2969    [007] .......   874.999179: tegra_channel_capture_frame: sof:939.145750496  
[16-28-44.910]  vi-output, lh_a-2969    [007] .......   874.999180: tegra_channel_capture_frame: eof:939.160890080

We would appreciate guidance on:
Modifying the time base configuration to unify timestamps.
Documentation references for timestamp generation mechanisms.
ASAP, Thanks.

5

Have check below topic.

6

hi ShaneCCC：

The version I’m using is R36.4.3, and there’s no parameter information for this:

root@tegra-ubuntu:~# cat /sys/devices/system/clocksource/clocksource0/offset_ns  
9045955168

Additionally, I found a similar version 6.0.10 API manual:

Is the calculation process there directly applicable to local static implementation?

In the current version’s timekeeping.h, I found these APIs, but the sof values all differ:

ktime_get_raw_ts64(&light_time);        → 98.388014912  
ktime_get_ts64(&light_time);            → 98.388029024  
ktime_get_boottime_ts64(&light_time);   → 98.388030304  
ktime_get_real_ts64(&light_time);       → 1763362441.923672256  
ktime_get_clocktai_ts64(&light_time);   → 1763362441.923672992  
tegra_channel_capture_frame: sof:162.532301824

Could you provide the clock_offset_ns value or calculation method for R36.4.3?

7

The document tell is how to get the offset by r36 release.