Bug:[Smartswitch] DPU's reboot cause is being checked when the operational state changes to offline

[gpunathilell]

Is it platform specific

generic

Importance or Severity

Critical

Description of the bug

In chassisd implementation, when the operational state of the DPU has transitioned to offline, we are querying the reboot cause of the DPU, this is irrelevant at this point of time because the reboot cause of the DPU needs to be checked after the DPU has completed rebooting, we are trying to access the DPUs reboot cause capabilities while the DPU is powered off,

Steps to Reproduce

power off DPU (config chassis modules shutdown DPU0) check logs:

2026 Mar  3 06:38:29.047071 sonic NOTICE pmon#chassisd: DPU2 operational status transitioning to offline
2026 Mar  3 06:38:29.076384 sonic NOTICE pmon#chassisd[39]: Reset reason for DPU2 is Non-Hardware

Actual Behavior and Expected Behavior

Actual behavior:
Checking for reboot cause when DPU is powered off
Expected behaviour:
Checking for reboot cause of DPU after it has powered on

Relevant log output

Output of show version, show techsupport

202511 latest hash

Attach files (if any)

No response