- /*
- * Above Trip?
- * -----------
- * Calculate the thermal trend (using the passive cooling equation)
- * and modify the performance limit for all passive cooling devices
- * accordingly. Note that we assume symmetry.
- */
- if (tz->temperature >= passive->temperature) {
- trend =
- (passive->tc1 * (tz->temperature - tz->last_temperature)) +
- (passive->tc2 * (tz->temperature - passive->temperature));
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "trend[%d]=(tc1[%lu]*(tmp[%lu]-last[%lu]))+(tc2[%lu]*(tmp[%lu]-psv[%lu]))\n",
- trend, passive->tc1, tz->temperature,
- tz->last_temperature, passive->tc2,
- tz->temperature, passive->temperature));
- passive->flags.enabled = 1;
- /* Heating up? */
- if (trend > 0)
- for (i = 0; i < passive->devices.count; i++)
- acpi_processor_set_thermal_limit(passive->
- devices.
- handles[i],
- ACPI_PROCESSOR_LIMIT_INCREMENT);
- /* Cooling off? */
- else if (trend < 0) {
- for (i = 0; i < passive->devices.count; i++)
- /*
- * assume that we are on highest
- * freq/lowest thrott and can leave
- * passive mode, even in error case
- */
- if (!acpi_processor_set_thermal_limit
- (passive->devices.handles[i],
- ACPI_PROCESSOR_LIMIT_DECREMENT))
- result = 0;
- /*
- * Leave cooling mode, even if the temp might
- * higher than trip point This is because some
- * machines might have long thermal polling
- * frequencies (tsp) defined. We will fall back
- * into passive mode in next cycle (probably quicker)
- */
- if (result) {
- passive->flags.enabled = 0;
- ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "Disabling passive cooling, still above threshold,"
- " but we are cooling down\n"));
- }