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*95°C for Consumer parts
*105°C for Industrial parts
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====U-Boot====
At U-Boot level, automatic boot procedure is halted until Tj is smaller than (following temperatures might seem excessively low but they take into account the intrinsic poor precision of the temperature sensor to provide a reasonable safe margin):
*TBD for Consumer parts*95°C for Industrial parts
====Linux kernel====
*for Consumer parts
** passive threshold: '''TBD'''** critical threshold: '''TBD'''
*for Industrial parts
** passive threshold: 85°C
Practically speaking, for DESK-MX8-L this mechanism makes use of two different thresholds, denoted as <code>trip_point0</code> (also known as ''passive threshold'') and <code>trip_point1</code> (also known as ''critical threshold)''.
When Tj reaches <code>trip_point0</code>, Linux kernel scales down processor frequency: <pre>System is too hot. GPU3D will work at 1/64 clock.</pre>
If Tj reaches <code>trip_point1</code>, a complete shutdown is triggered:
<pre>
thermal thermal_zone0: critical temperature reached(100 95 C),shutting down
</pre>
Trip point thresholds can be accessed via <code>sysfs</code> interface from user space. The following example shows how to read the values of the trip points:
<pre>
root@axel-litemito:~# cat /sys/devices/virtual/thermal/thermal_zone0/trip_point_0_temp
85000
root@axel-litemito:~# cat /sys/devices/virtual/thermal/thermal_zone0/trip_point_1_temp100000950000
</pre>
This example shows how to set trip points 0 and 1 to 95°C and 100°C respectively:
echo 100000 > /sys/class/thermal/thermal_zone0/trip_point_1_temp
</pre>
To read current processor temperature please issue this command (reported temperature is 36.676°C in the example):
<pre>
root@axel-litemito:~# cat /sys/class/thermal/thermal_zone0/temp
36676
</pre>