Hi, this is related to: commit fa80945269f312bc609e8384302f58b03c916e12 ACPI thermal: Don't invalidate thermal zone if critical trip point is bad and commit 8b7ef6d8f16274da42344cd50746ddb1c93c25ea ACPI thermal: Check for thermal zone requirement There the critical trip point is replaced with the hot trip point if latest Windows OS is detected (Vista also? I think yes, but need to double check). This seem to get more common and it looks like Windows suggests to use hot trip points for thermal emergency shutdowns (S4). It looks like the default Windows thermal emergency power off is S4. Thus the hot trip point is used and the critical trip point is of no use anymore (and often gets replaced or is invalid). As thermal emergency shut down is something urgent there is this direct call /sbin/poweroff in orderly_poweroff(true) compare with kernel/sys.c and drivers/thermal/thermal_sys.c This won't work in above cases when BIOS writers assume the machine is shut down with _HOT already and do not provide _CRT anymore. My idea is to also shutdown the system on _HOT by default, the same way as done if _CRT is exceeded as long as no userspace explicitly set a sysfs (only one file set by thermal_sys.c somewhere in /sys?). Background is that S4 needs some setup (e.g. swap) or userspace hooks to make sure S4 succeeds and everything (network, whatever...) is set up correctly afterwards. Requirement for the userspace tool setting the "do not shutdown if a hot thermal event happened" would be: - Fetch the thermal hot event - Reliably power off the system (shutdown if S4 did not succeed) - ... Comments? What userspace tools are candidates to implement this if this makes sense? Thanks, Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html