tree 5ee5303766a29dfb3d98bab3ced1de18e2f57574
parent d0ccda3c2a36625d30a6c3b70ed0216694102fed
author Matt Spinler <spinler@us.ibm.com> 1683223724 -0500
committer Matt Spinler <spinler@us.ibm.com> 1683906409 -0500

PEL: Watch for fan/PS hotplugs

Code is going to need to know when a fan or power supply (the only
hotpluggable redundant FRUs) are added or replaced so that it can clear
a flag in PELs that have that HW as a callout.  This is so other code
that is doing degraded mode notifications will not do any notifications
for PELs calling out HW that has been replaced.

To enable this functionality, add support to the DataInterface class to
tell subscribers via a function callback when a fan or power supply
becomes present, as indicated by the Present property.

Code will watch the Present property of fan and power supplies to change
via the PropertiesChanged signal, as well as watch for InterfacesAdded
to catch when they show up on D-Bus in the first place.

It won't start any of these watches until the BMC gets to ready state so
that the inventory has a chance to be populated first.

On the first boot when the inventory was previously empty there will be
a round of inventory InterfacesAdded signals that will wake up the
daemon when PLDM receives the processor core presence information from
hostboot, but it just checks and sees it's the wrong interface and
returns, and I'm not sure how it can be avoided.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I93d0727c3082677826db4a4a02c1a30986f6099b