tree 270d0ce81a75ee6a9cf05d5920985b1b3daf4a98
parent 678f53b88861f14da4884f57d8e172a0604a1569
author Zhikui Ren <zhikui.ren@intel.com> 1607037289 -0800
committer Ed Tanous <ed@tanous.net> 1618511770 +0000

Fix ExitAirTempSensor calculation

When calculating maxRPM, variables tachMaxPercent and tachMinPercent
are in percentage. Both tachMaxReading and tachMinReading are already
specified as percentage in configuration file.

When cfm is less than 50% of QMin, exit air temp formula does not
work correctly. Make exit air temp not available.

Use steady_clock to ensure time elapsed is non-negative.

Increase the error print count to 5 during exit air temp computation.
This change allows power reading related error messages to be logged
in addition to fan sensor reading errors during same computation cycle.

This patch also includes minor clean up that moves powerReading
to private member.

Tested:
Before the change, exit air temp reports critical event occasionally on power up.
Examples:
Exit_Air_Temp sensor crossed a critical high threshold going high. Reading=13938.000000 Threshold=85.000000
Exit_Air_Temp sensor crossed a critical low threshold going low. Reading=-119240.000000 Threshold=0.000000

Same AC cycle test was run with the change, the issue is resolved.

Signed-off-by: Zhikui Ren <zhikui.ren@intel.com>
Change-Id: Idf9c2aa916ac741ff047c5baea51a664c101c33d