Enable system WDT with timeout of 8s - Githubissues

system76 / ec

System76 Open Source Embedded Controller

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Enable system WDT with timeout of 8s #487

Open crawfxrd opened 1 month ago

crawfxrd commented 1 month ago

Enable WDT to ensure the system:

Does not hang processing any task, such as previous cases of PECI commands never completing.
Does not take longer than the timeout period to complete all outstanding tasks.

A timeout of 8s is used to remain close to the existing use of the WDT in scratch ROM, which was set to 10s.

Ref: #389

Testing

That it works as intended:
1. Flash custom build with debug logging enabled and wdt_kick removed from main loop
2. Plug in the unit
3. Observe EC init message ("System76 EC board...") occurs every ~8.1 seconds
Standard firmware validation tasks do not result in unexpected power off

TODO

Allow user to still boot system in case of WDT being constantly triggered
1. Determine if last reset source (RSTS[1:0]) is external WDT
2. Boot with WDT, other functions disabled? (recovery/emergency/crisis mode)
3. Propagate error to system firmware, OS