linux-surface/contrib/thermald/surface_pro_5

thermald configuration tweaked for Surface Pro 5

• thermald configuration starting point: https://github.com/intel/dptfxtract
  • by default it uses sensor "GEN4", which is for the NVME drive, not good.
  • pch_skylake is a better choice here.
• Takes care of surface profile set {low-power|performance} on power supply events.
• Restarts thermald on power events to load corresponding thermal profiles.
• There are 3 thermal profiles here:
  • thermal-conf.xml.auto.performance: activated on AC power. Runs at peak performance (~25watts) until reaching 60 degrees. Stabilized at ~15watts under heavy load.
  • thermal-conf.xml.auto.mobile: activated on battery. Throttles early for ~15watts. Throttles to ~8watts for heavy load. Try to keep the device cool.
  • thermal-conf.xml.auto.cool: reserved.

Basically, we are just using RAPL here to throttle the power (in watts), not the frequency of the CPU, and it's more fine-grained and aligned with our thermal targets.

See 40-surface-power.rules for more details on how to obtain info about sensors and cooling devices.

Bonus

40-surface-power.rules also contains power-related tweaks for:

• surface profile: currently low-power vs. performance
• Various PCIe powersaving strategies
• Intel p-state control for turbo-boost

50-surface.conf contains sysctl tweaks advised by powertop.

Installation

• Make sure to install surface-control
• Install 40-surface-power.rules to /usr/lib/udev/rules.d/
• Install thermal-conf.xml* to /etc/thermald/
  • thermal-conf.xml.auto will be linked dynamically by the udev rule file.
• Install thermal-cpu-cdev-order.xml to /etc/thermald/
• Install thermald.service to /lib/systemd/system/ and overwrite the old one.
  • Maybe install to /usr/lib/systemd/system/ too.
• Install 50-surface.conf to /etc/sysctl.d/
• systemctl daemon-reload
• systemctl restart udev
• systemctl restart thermald