ACPI: Allow overriding to higher critical trip point. (22a94d79) · Commits · 戴 / test

http://bugzilla.kernel.org/show_bug.cgi?id=9129 lenb: Note that overriding a critical trip point may simply fool the user into thinking that they have control that they do not actually have. For it is EC firmware that decides when the EC sends Linux temperature change events, and the EC may or may not decide to send Linux these events anywhere in the neighborhood of the fake override trip points. Beware. note also that thermal.nocrt is already available to disable crtical trip point actios, and thermal.crt=-1 is already available to disabled critical trip points entirely. Signed-off-by:

Zhang Rui <rui.zhang@intel.com> Signed-off-by:

Len Brown <len.brown@intel.com>

Documentation/kernel-parameters.txt

+1 −1

Original line number	Diff line number	Diff line
		@@ -2146,7 +2146,7 @@ and is between 256 and 4096 characters. It is defined in the file

		thermal.crt= [HW,ACPI]
		-1: disable all critical trip points in all thermal zones
		<degrees C>: lower all critical trip points
		<degrees C>: override all critical trip points

		thermal.nocrt= [HW,ACPI]
		Set to disable actions on ACPI thermal zone

drivers/acpi/thermal.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -388,9 +388,11 @@ static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
		} else if (crt > 0) {
		unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
		/*
		* Allow override to lower critical threshold
		* Allow override critical threshold
		*/
		if (crt_k < tz->trips.critical.temperature)
		if (crt_k > tz->trips.critical.temperature)
		printk(KERN_WARNING PREFIX
		"Critical threshold %d C\n", crt);
		tz->trips.critical.temperature = crt_k;
		}
		}

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