[barefoot][platform] Chassis.get_reboot_cause

[vboykox]

Signed-off-by: Volodymyr Boyko volodymyrx.boiko@intel.com

Why I did it

To fix determine-reboot-cause service which was failing due to non-implemented thrown from get_reboot_case, if the reboot was done with sudo reboot (cold reboot)

How I did it

Added get_reboot_case implementation that will always return Non-Hardware reason.

How to verify it

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012

Description for the changelog

barefoot implementation of sonic_platform.chassis.Chassis.get_reboot_cause

A picture of a cute animal (not mandatory but encouraged)

[vboykox]

@akokhan

[vboykox]

@jleveque to me it looks confusing that if platform does not support determining any of REBOOT_CAUSE_ it should return Non-Hardware to make determine-reboot-cause work.
imho REBOOT_CAUSE_NON_HARDWARE should only mean none of other conditions, which could be tracked by platform (power loss, etc), happened.
The alternative PR: #7796

[jleveque]

@jleveque to me it looks confusing that if platform does not support determining any of REBOOT_CAUSE_ it should return Non-Hardware to make determine-reboot-cause work.
imho REBOOT_CAUSE_NON_HARDWARE should only mean none of other conditions, which could be tracked by platform (power loss, etc), happened.
The alternative PR: #7796

REBOOT_CAUSE_NON_HARDWARE implies that a hardware-initiated reboot cause (e.g., power loss, thermal overload, etc.) did not occur. If the platform doesn't support detecting any hardware-initiated reboot causes, then REBOOT_CAUSE_NON_HARDWARE makes sense, because we were unable to determine that a hardware-initiated reboot occurred.

Your platform doesn't support detecting any hardware-initiated reboot causes?

[vboykox]

@jleveque For now we will not support it in SONiC.
So we have to state that reason is not hardware even if device lost power. There is no "I don't know" option.

[jleveque]

@jleveque For now we will not support it in SONiC.
So we have to state that reason is not hardware even if device lost power. There is no "I don't know" option.

If the platform API returns REBOOT_CAUSE_NON_HARDWARE, the reboot cause determination logic will check to see if a software reboot was initiated. If there is no record of a software reboot, the reboot cause will be "Unknown". So in your case, if a hardware-initiated reboot occurs but you return REBOOT_CAUSE_NON_HARDWARE, the reboot cause should be "Unknown".

[vboykox]

@jleveque Yes, specifically for determine-reboot-cause, it makes sense to return NON_HARDWARE in combination with sw cause check.
Thank you for explanation!

[vboykox]

@lguohan

[vboykox]

@lguohan