RE: Lid support for ACPI

From: Grover, Andrew (
Date: Mon Apr 30 2001 - 00:00:05 EST

(btw ACPI 2.0 spec section 12.1.1 discusses this)

> From: Pavel Machek []
> > No, the ACPI standard requires CPUs to shut themselves down before
> > any damage would occur from overheading. Well, at least the 1.0b
> > version of the standard did; I haven't read 2.0 yet.

> BTW shut themselves down to halt, or shut themselves to
> *very* low speed?

Both. When a CPU overheats, the OS implements either active (turning on a
fan) or passive (cpu throttling). If the temperature still exceeds the
critical threshold, the OS must shut down.

> Slow down to 10% speed is what my toshiba does. Is there way
> back from such
> mode?

Once the temperature drops below the active and passive cooling thresholds,
the OS should stop its cooling measures, such as throttling.

That said, I seem to recall your laptop is doing throttling in a non-OS
visible way (BIOS) so I don't know under what circumstances it stops cpu

Regards -- Andy

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Mon Apr 30 2001 - 21:00:23 EST