[PATCH] ACPI thermal: Don't invalidate thermal zone if critical trip point is bad

Thomas Renninger
2010-02-20T10:20:47Z

Some BIOSes return a negative value for the critical trip point.
We currently invalidate the whole thermal zone in this case.
But it may still be needed for cooling, also without critical
trip point:

Same if there is no critical trip point, but ACPI spec says
there must at least be one trip point, it need not to be a
critical (see next patch).

Reference: http://bugzilla.novell.com/show_bug.cgi?id=531547

Signed-off-by: Thomas Renninger <trenn@suse.de>
Tested-by: clarkt@cnsp.com
CC: Len Brown <lenb@kernel.org>
CC: linux-acpi@vger.kernel.org
---
drivers/acpi/thermal.c | 18 ++++++++++--------
1 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 9073ada..8fa71b8 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -368,7 +368,7 @@ static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
int valid = 0;
int i;

- /* Critical Shutdown (required) */
+ /* Critical Shutdown */
if (flag & ACPI_TRIPS_CRITICAL) {
status = acpi_evaluate_integer(tz->device->handle,
"_CRT", NULL, &tmp);
@@ -379,17 +379,19 @@ static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
* Below zero (Celsius) values clearly aren't right for sure..
* ... so lets discard those as invalid.
*/
- if (ACPI_FAILURE(status) ||
- tz->trips.critical.temperature <= 2732) {
+ if (ACPI_FAILURE(status)) {
+ tz->trips.critical.flags.valid = 0;
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "No critical threshold\n"));
+ } else if (tmp <= 2732) {
+ printk(KERN_WARNING FW_BUG "Invalid critical threshold "
+ "(_CRT:%)\n", tmp);
tz->trips.critical.flags.valid = 0;
- ACPI_EXCEPTION((AE_INFO, status,
- "No or invalid critical threshold"));
- return -ENODEV;
} else {
tz->trips.critical.flags.valid = 1;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "Found critical threshold [%lu]\n",
- tz->trips.critical.temperature));
+ "Found critical threshold [%lu]\n",
+ tz->trips.critical.temperature));
}
if (tz->trips.critical.flags.valid == 1) {
if (crt == -1) {
--
1.6.3