On Wed, 4 Feb 2009, Matthew Garrett wrote: > On Wed, Feb 04, 2009 at 12:52:06AM -0500, Len Brown wrote: > > > While it is slightly off-topic of the (I agree, real) > > technical issue here, note that polling is not "normal" on ACPI systems. > > [1] was on SuSE Linux 10.0, which on their own decided to > > over-ride the kernel and enable thermal zone polling by default. > > Checking the DSDTs I have to hand, it seems that polling is expected on > about 5% of systems via an explicit _TZP and on almost all machines via > _TSP. Even on systems where thermal notifications are provided, it's > still up to the OS to poll the zone to find the current temperature and > take appropriate action. There's still a window for native smbus drivers > to screw everything up. FWIW In the last 6 years, I've seen exactly 3 systems with a non-zero _TZP. An old Averatec laptop asked for 1 second, and two recent EEE-PC's ask for 30 seconds. Dunno why Asus has made this leap backwards. _TSP is a different beast. It only exists in the context of _PSV and _PSL. -Len ps. I just noticed something in the spec under _PSL... "If a linear performance control register is not defined(..) for a processor defined in _PSL or for a processor device in the zone as indicated by _TZM, then the processor must support processor performance states (in other words, the processor's processor object must include _PCT, _PSS, and _PPC). Interesting, here is an official tie in of P-states and passive trip points that I'd not noticed before.... -- 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
