Use vendor customizable fan speed threshold checks

[spilkey-cisco]

Description

Use vendor customizable fan speed threshold checks in thermalctld instead of hard-coded calculations based on pwm/percentage speed.

Motivation and Context

Fan under/over speed checks should be vendor customizable, since a tolerance based off the pwm/percentage fan speed can easily give false failures, especially for low fan speeds.

How Has This Been Tested?

root@sonic:/home/cisco# echo 10000 > /opt/cisco/etc/fantray0.fan0.rpm
root@sonic:/home/cisco# grep thermalctld /var/log/syslog
<snip>
May 19 05:09:47.763970 sonic WARNING pmon#thermalctld: Fan high speed warning: fantray0.fan0 current speed=91, target speed=20
May 19 05:09:51.129298 sonic INFO pmon#supervisord 2023-05-19 05:09:51,128 INFO success: thermalctld entered RUNNING state, process has stayed up for > than 10 seconds (startsecs)
May 19 05:10:01.347935 sonic INFO pmon#supervisord: thermalctld WARNING:cisco.pacific.thermal.thermal_zone:level minor: fantray0.fan0: pwm 20; motor out of tolerance @ rpm 10000; maximum rpm 2950
root@sonic:/home/cisco# echo 2400 > /opt/cisco/etc/fantray0.fan0.rpm
root@sonic:/home/cisco# grep thermalctld /var/log/syslog
<snip>
May 19 05:09:47.763970 sonic WARNING pmon#thermalctld: Fan high speed warning: fantray0.fan0 current speed=91, target speed=20
May 19 05:09:51.129298 sonic INFO pmon#supervisord 2023-05-19 05:09:51,128 INFO success: thermalctld entered RUNNING state, process has stayed up for > than 10 seconds (startsecs)
May 19 05:10:01.347935 sonic INFO pmon#supervisord: thermalctld WARNING:cisco.pacific.thermal.thermal_zone:level minor: fantray0.fan0: pwm 20; motor out of tolerance @ rpm 10000; maximum rpm 2950
May 19 05:10:47.023156 sonic NOTICE pmon#thermalctld: Fan high speed warning cleared: fantray0.fan0 speed is back to normal

[amulyan7]

LGTM

[bmridul]

Is it better to check if this function is not implemented and fall back to old code than putting an implementation in the base class (which one would not understand unless he knew about this change) esp because the changes span across repos.

[spilkey-cisco]

Having a default implementation in the base class allows for the same calculation to be used across other code, such as sonic-mgmt tests. If we fall back to a hard-coded calculation inside thermalctld, then the calculation must also be hard-coded anywhere else fan under/over speed conditions should be checked. Existing sonic-mgmt speed tolerance checks use different (and incorrect) calculation logic, so having a default API implementation solves this issue (https://wwwin-github.cisco.com/spilkey/sonic-test/pull/1)

[spilkey-cisco]

Closing to open new PR to merge into sonic-net/sonic-platform-daemons

[spilkey-cisco]

sonic-net#378