[PATCH v1 1/9] ACPI: thermal: Simplify initialization of critical and hot trips

Rafael J. Wysocki
2023-09-12T18:48:13Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Use the observation that the critical and hot trip points are never
updated by the ACPI thermal driver, because the flags passed from
acpi_thermal_notify() to acpi_thermal_trips_update() do not include
ACPI_TRIPS_CRITICAL or ACPI_TRIPS_HOT, to move the initialization
of those trip points directly into acpi_thermal_get_trip_points() and
reduce the size of __acpi_thermal_trips_update().

Also make the critical and hot trip points initialization code more
straightforward and drop the flags that are not needed any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/thermal.c | 130 ++++++++++++++++++++++++-------------------------
1 file changed, 66 insertions(+), 64 deletions(-)

Index: linux-pm/drivers/acpi/thermal.c
===================================================================
--- linux-pm.orig/drivers/acpi/thermal.c
+++ linux-pm/drivers/acpi/thermal.c
@@ -43,17 +43,13 @@
#define ACPI_THERMAL_MAX_ACTIVE 10
#define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65

-#define ACPI_TRIPS_CRITICAL BIT(0)
-#define ACPI_TRIPS_HOT BIT(1)
-#define ACPI_TRIPS_PASSIVE BIT(2)
-#define ACPI_TRIPS_ACTIVE BIT(3)
-#define ACPI_TRIPS_DEVICES BIT(4)
+#define ACPI_TRIPS_PASSIVE BIT(0)
+#define ACPI_TRIPS_ACTIVE BIT(1)
+#define ACPI_TRIPS_DEVICES BIT(2)

#define ACPI_TRIPS_THRESHOLDS (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)

-#define ACPI_TRIPS_INIT (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT | \
- ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE | \
- ACPI_TRIPS_DEVICES)
+#define ACPI_TRIPS_INIT (ACPI_TRIPS_THRESHOLDS | ACPI_TRIPS_DEVICES)

/*
* This exception is thrown out in two cases:
@@ -196,62 +192,6 @@ static void __acpi_thermal_trips_update(
bool valid = false;
int i;

- /* Critical Shutdown */
- if (flag & ACPI_TRIPS_CRITICAL) {
- status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
- tz->trips.critical.temperature = tmp;
- /*
- * Treat freezing temperatures as invalid as well; some
- * BIOSes return really low values and cause reboots at startup.
- * Below zero (Celsius) values clearly aren't right for sure..
- * ... so lets discard those as invalid.
- */
- if (ACPI_FAILURE(status)) {
- tz->trips.critical.valid = false;
- acpi_handle_debug(tz->device->handle,
- "No critical threshold\n");
- } else if (tmp <= 2732) {
- pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
- tz->trips.critical.valid = false;
- } else {
- tz->trips.critical.valid = true;
- acpi_handle_debug(tz->device->handle,
- "Found critical threshold [%lu]\n",
- tz->trips.critical.temperature);
- }
- if (tz->trips.critical.valid) {
- if (crt == -1) {
- tz->trips.critical.valid = false;
- } else if (crt > 0) {
- unsigned long crt_k = celsius_to_deci_kelvin(crt);
-
- /*
- * Allow override critical threshold
- */
- if (crt_k > tz->trips.critical.temperature)
- pr_info("Critical threshold %d C\n", crt);
-
- tz->trips.critical.temperature = crt_k;
- }
- }
- }
-
- /* Critical Sleep (optional) */
- if (flag & ACPI_TRIPS_HOT) {
- status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
- if (ACPI_FAILURE(status)) {
- tz->trips.hot.valid = false;
- acpi_handle_debug(tz->device->handle,
- "No hot threshold\n");
- } else {
- tz->trips.hot.temperature = tmp;
- tz->trips.hot.valid = true;
- acpi_handle_debug(tz->device->handle,
- "Found hot threshold [%lu]\n",
- tz->trips.hot.temperature);
- }
- }
-
/* Passive (optional) */
if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.trip.valid) ||
flag == ACPI_TRIPS_INIT) {
@@ -451,11 +391,73 @@ static void acpi_thermal_trips_update(st
dev_name(&adev->dev), event, 0);
}

+static void acpi_thermal_get_critical_trip(struct acpi_thermal *tz)
+{
+ unsigned long long tmp;
+ acpi_status status;
+
+ if (crt > 0) {
+ tmp = celsius_to_deci_kelvin(crt);
+ goto set;
+ }
+ if (crt == -1) {
+ acpi_handle_debug(tz->device->handle, "Critical threshold disabled\n");
+ goto fail;
+ }
+
+ status = acpi_evaluate_integer(tz->device->handle, "_CRT", NULL, &tmp);
+ if (ACPI_FAILURE(status)) {
+ acpi_handle_debug(tz->device->handle, "No critical threshold\n");
+ goto fail;
+ }
+ if (tmp <= 2732) {
+ /*
+ * Below zero (Celsius) values clearly aren't right for sure,
+ * so discard them as invalid.
+ */
+ pr_info(FW_BUG "Invalid critical threshold (%llu)\n", tmp);
+ goto fail;
+ }
+
+set:
+ tz->trips.critical.valid = true;
+ tz->trips.critical.temperature = tmp;
+ acpi_handle_debug(tz->device->handle, "Critical threshold [%lu]\n",
+ tz->trips.critical.temperature);
+ return;
+
+fail:
+ tz->trips.critical.valid = false;
+ tz->trips.critical.temperature = THERMAL_TEMP_INVALID;
+}
+
+static void acpi_thermal_get_hot_trip(struct acpi_thermal *tz)
+{
+ unsigned long long tmp;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(tz->device->handle, "_HOT", NULL, &tmp);
+ if (ACPI_FAILURE(status)) {
+ tz->trips.hot.valid = false;
+ tz->trips.hot.temperature = THERMAL_TEMP_INVALID;
+ acpi_handle_debug(tz->device->handle, "No hot threshold\n");
+ return;
+ }
+
+ tz->trips.hot.valid = true;
+ tz->trips.hot.temperature = tmp;
+ acpi_handle_debug(tz->device->handle, "Hot threshold [%lu]\n",
+ tz->trips.hot.temperature);
+}
+
static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
{
bool valid;
int i;

+ acpi_thermal_get_critical_trip(tz);
+ acpi_thermal_get_hot_trip(tz);
+ /* Passive and active trip points (optional). */
__acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);

valid = tz->trips.critical.valid |