Improve robustness of hwp_pcu

[ykyohei]

This PR will make the pcu agent robust against usb connection dropouts #796

Description

Improve robustness of pcu against usb connection dropouts

Motivation and Context

#796

How Has This Been Tested?

Under testing at satp3 -> tested!

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[ykyohei]

I make this PR ready, reconnection is tested as follows at satp3.

2024-11-23T14:07:26+0000 Status is failed, cleared buffer
2024-11-23T14:07:23+0000 Cleared buffer
2024-11-23T14:07:22+0000 Connected to PCU
2024-11-23T14:06:52+0000 Decive reports readiness to read but returned no data. Reconnect after 30 sec...
2024-11-23T14:00:13+0000 Status is failed, cleared buffer
2024-11-23T14:00:09+0000 Cleared buffer
2024-11-23T14:00:08+0000 Connected to PCU
2024-11-23T13:59:38+0000 Decive reports readiness to read but returned no data. Reconnect after 30 sec...
2024-11-23T13:57:41+0000 send_command:5 Status is now "done".
2024-11-23T13:57:41+0000 send_command:5 Set relays for cmd=stop
2024-11-23T13:57:41+0000 Command: stop
2024-11-23T13:57:39+0000 Running action Actions.SendCommand(command='stop')

[BrianJKoopman]

This looks good, thanks for the PR! Just two small comments.

[BrianJKoopman]

This continue isn't needed, since it's the last statement in the loop that it's continuing.

[BrianJKoopman]

There's already a 30 second sleep on the reconnect logic in line 124/125, so I'd say you can drop this here. If it can reconnect it'll do so quickly, if it can't it'll wait 30 seconds already.

[jlashner]

Thanks Kyohei, this looks good to me!

[BrianJKoopman]

Thanks for the updates!