presence: Sensor conflict checking for AnyOf
There can be more than one way to detect the presence of a fan, such as
by a GPIO and by a nonzero tach reading. The AnyOf redundancy policy
only requires one of these to indicate present when determining the
overall fan presence state.
This commit adds the functionality to check for the case when one of the
method reports not present while another reports present. In this case,
the one reporting not present will be considered the wrong one, and
depending on the detection type either an information event log or just
a journal trace will be created.
Only one log per method per power cycle will occur. Since one of the
methods probably looks for nonzero tach readings, there is a 5 second
delay after a power on is detected before a conflict check is done.
If the GPIO method is where the problem is detected, an event log is
created. If it's instead the tach sensor method, then a trace will just
be put in the journal because there is already code watching for and
creating event logs for stopped tachs - the fan monitor code.
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I72a764ecff4076d6dc40335b92d177b6b3cfa2d9
9 files changed