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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-06-06 20:27:30 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2024-06-07 13:52:17 +0200 |
| commit | 7f18bd49cb6b6a3ab6d860fefccdc94f2a247db0 (patch) | |
| tree | 6b122b1758b1758306f0ba01055285d2a4658dd8 | |
| parent | 1af89dedc8a58006d8e385b1e0d2cd24df8a3b69 (diff) | |
| download | lwn-7f18bd49cb6b6a3ab6d860fefccdc94f2a247db0.tar.gz lwn-7f18bd49cb6b6a3ab6d860fefccdc94f2a247db0.zip | |
thermal: ACPI: Invalidate trip points with temperature of 0 or below
It is reported that commit 950210887670 ("thermal: core: Drop
trips_disabled bitmask") causes the maximum frequency of CPUs to drop
further down with every system sleep-wake cycle on Intel Core i7-4710HQ.
This turns out to be due to a trip point whose temperature is equal to 0
degrees Celsius which is acted on every time the system wakes from sleep.
Before commit 950210887670 this trip point would be disabled wia the
trips_disabled bitmask, but now it is treated as a valid one.
Since ACPI thermal control is generally about protection against
overheating, trip points with temperature of 0 centigrade or below are
not particularly useful there, so initialize them all as invalid which
fixes the problem at hand.
Fixes: 950210887670 ("thermal: core: Drop trips_disabled bitmask")
Closes: https://lore.kernel.org/linux-pm/3f71747b-f852-4ee0-b384-cf46b2aefa3f@gmx.com
Reported-by: Tibor Billes <tbilles@gmx.com>
Tested-by: Tibor Billes <tbilles@gmx.com>
Cc: 6.7+ <stable@vger.kernel.org> # 6.7+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/acpi/thermal.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c index d67881b50bca..a0cfc857fb55 100644 --- a/drivers/acpi/thermal.c +++ b/drivers/acpi/thermal.c @@ -168,11 +168,17 @@ static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz) static int acpi_thermal_temp(struct acpi_thermal *tz, int temp_deci_k) { + int temp; + if (temp_deci_k == THERMAL_TEMP_INVALID) return THERMAL_TEMP_INVALID; - return deci_kelvin_to_millicelsius_with_offset(temp_deci_k, + temp = deci_kelvin_to_millicelsius_with_offset(temp_deci_k, tz->kelvin_offset); + if (temp <= 0) + return THERMAL_TEMP_INVALID; + + return temp; } static bool acpi_thermal_trip_valid(struct acpi_thermal_trip *acpi_trip) |