From a39a2d7c72b358c6253a2ec28e17b023b7f6f41c Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 19 May 2008 15:55:15 -0700 Subject: ACPI: Reject below-freezing temperatures as invalid critical temperatures My laptop thinks that it's a good idea to give -73C as the critical CPU temperature.... which isn't the best thing since it causes a shutdown right at bootup. Temperatures below freezing are clearly invalid critical thresholds so just reject these as such. Signed-off-by: Arjan van de Ven Acked-by: Zhang Rui Signed-off-by: Len Brown --- drivers/acpi/thermal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/thermal.c') diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c index 504385b1f211..84c795fb9b1e 100644 --- a/drivers/acpi/thermal.c +++ b/drivers/acpi/thermal.c @@ -364,10 +364,17 @@ static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag) if (flag & ACPI_TRIPS_CRITICAL) { status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tz->trips.critical.temperature); - if (ACPI_FAILURE(status)) { + /* + * Treat freezing temperatures as invalid as well; some + * BIOSes return really low values and cause reboots at startup. + * Below zero (Celcius) values clearly aren't right for sure.. + * ... so lets discard those as invalid. + */ + if (ACPI_FAILURE(status) || + tz->trips.critical.temperature <= 2732) { tz->trips.critical.flags.valid = 0; ACPI_EXCEPTION((AE_INFO, status, - "No critical threshold")); + "No or invalid critical threshold")); return -ENODEV; } else { tz->trips.critical.flags.valid = 1; -- cgit v1.2.3