a000298_approval, dave_user
299
edits
Changes
→Linux kernel
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
*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>
85000
root@mito:~# cat /sys/devices/virtual/thermal/thermal_zone0/trip_point_1_temp
</pre>
This example shows how to set trip points 0 and 1 to 95°C and 100°C respectively:
'''Please note that:'''
*it is possible to set up trip points greater than the maximum junction temperature indicated by manufacturer datasheet;*exceeding maximum junction temperature indicated by manufacturer datasheet may cause permanent damage.
To read current processor temperature please issue this command (reported temperature is 36.676°C in the example):
