freebsd-skq/sys/powerpc/powermac/powermac_thermal.c
jhibbits 42d5cba910 Make the PowerMac fan control nonlinear
Summary:
Currently, fan control is linear between the target temperature and max
temperature, which is far from ideal.  This changes it to be proportional to the
distance between the current temperature and the two endpoints (target and max
temp).  This also adds a hysteresis, so that fans keep going when the
temperature drops, for about 10 seconds, before slowing down.

Reviewers: nwhitehorn

Reviewed By: nwhitehorn

Differential Revision: https://reviews.freebsd.org/D1549

MFC after:	3 weeks
2015-02-20 06:19:23 +00:00

219 lines
6.1 KiB
C

/*-
* Copyright (c) 2009-2011 Nathan Whitehorn
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/queue.h>
#include "powermac_thermal.h"
/* A 10 second timer for spinning down fans. */
#define FAN_HYSTERESIS_TIMER 10
static void fan_management_proc(void);
static void pmac_therm_manage_fans(void);
static struct proc *pmac_them_proc;
static int enable_pmac_thermal = 1;
static struct kproc_desc pmac_therm_kp = {
"pmac_thermal",
fan_management_proc,
&pmac_them_proc
};
SYSINIT(pmac_therm_setup, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, kproc_start,
&pmac_therm_kp);
SYSCTL_INT(_machdep, OID_AUTO, manage_fans, CTLFLAG_RW | CTLFLAG_TUN,
&enable_pmac_thermal, 1, "Enable automatic fan management");
static MALLOC_DEFINE(M_PMACTHERM, "pmactherm", "Powermac Thermal Management");
struct pmac_fan_le {
struct pmac_fan *fan;
int last_val;
int timer;
SLIST_ENTRY(pmac_fan_le) entries;
};
struct pmac_sens_le {
struct pmac_therm *sensor;
int last_val;
#define MAX_CRITICAL_COUNT 6
int critical_count;
SLIST_ENTRY(pmac_sens_le) entries;
};
static SLIST_HEAD(pmac_fans, pmac_fan_le) fans = SLIST_HEAD_INITIALIZER(fans);
static SLIST_HEAD(pmac_sensors, pmac_sens_le) sensors =
SLIST_HEAD_INITIALIZER(sensors);
static void
fan_management_proc(void)
{
/* Nothing to manage? */
if (SLIST_EMPTY(&fans))
kproc_exit(0);
while (1) {
pmac_therm_manage_fans();
pause("pmac_therm", hz);
}
}
static void
pmac_therm_manage_fans(void)
{
struct pmac_sens_le *sensor;
struct pmac_fan_le *fan;
int average_excess, max_excess_zone, frac_excess;
int fan_speed;
int nsens, nsens_zone;
int temp;
if (!enable_pmac_thermal)
return;
/* Read all the sensors */
SLIST_FOREACH(sensor, &sensors, entries) {
temp = sensor->sensor->read(sensor->sensor);
if (temp > 0) /* Use the previous temp in case of error */
sensor->last_val = temp;
if (sensor->last_val > sensor->sensor->max_temp) {
sensor->critical_count++;
printf("WARNING: Current temperature (%s: %d.%d C) "
"exceeds critical temperature (%d.%d C); "
"count=%d\n",
sensor->sensor->name,
(sensor->last_val - ZERO_C_TO_K) / 10,
(sensor->last_val - ZERO_C_TO_K) % 10,
(sensor->sensor->max_temp - ZERO_C_TO_K) / 10,
(sensor->sensor->max_temp - ZERO_C_TO_K) % 10,
sensor->critical_count);
if (sensor->critical_count >= MAX_CRITICAL_COUNT) {
printf("WARNING: %s temperature exceeded "
"critical temperature %d times in a row; "
"shutting down!\n",
sensor->sensor->name,
sensor->critical_count);
shutdown_nice(RB_POWEROFF);
}
} else {
if (sensor->critical_count > 0)
sensor->critical_count--;
}
}
/* Set all the fans */
SLIST_FOREACH(fan, &fans, entries) {
nsens = nsens_zone = 0;
average_excess = max_excess_zone = 0;
SLIST_FOREACH(sensor, &sensors, entries) {
temp = imin(sensor->last_val,
sensor->sensor->max_temp);
frac_excess = (temp -
sensor->sensor->target_temp)*100 /
(sensor->sensor->max_temp - temp + 1);
if (frac_excess < 0)
frac_excess = 0;
if (sensor->sensor->zone == fan->fan->zone) {
max_excess_zone = imax(max_excess_zone,
frac_excess);
nsens_zone++;
}
average_excess += frac_excess;
nsens++;
}
average_excess /= nsens;
/* If there are no sensors in this zone, use the average */
if (nsens_zone == 0)
max_excess_zone = average_excess;
/* No sensors at all? Use default */
if (nsens == 0) {
fan->fan->set(fan->fan, fan->fan->default_rpm);
continue;
}
/*
* Scale the fan linearly in the max temperature in its
* thermal zone.
*/
max_excess_zone = imin(max_excess_zone, 100);
fan_speed = max_excess_zone *
(fan->fan->max_rpm - fan->fan->min_rpm)/100 +
fan->fan->min_rpm;
if (fan_speed >= fan->last_val) {
fan->timer = FAN_HYSTERESIS_TIMER;
fan->last_val = fan_speed;
} else {
fan->timer--;
if (fan->timer == 0) {
fan->last_val = fan_speed;
fan->timer = FAN_HYSTERESIS_TIMER;
}
}
fan->fan->set(fan->fan, fan->last_val);
}
}
void
pmac_thermal_fan_register(struct pmac_fan *fan)
{
struct pmac_fan_le *list_entry;
list_entry = malloc(sizeof(struct pmac_fan_le), M_PMACTHERM,
M_ZERO | M_WAITOK);
list_entry->fan = fan;
SLIST_INSERT_HEAD(&fans, list_entry, entries);
}
void
pmac_thermal_sensor_register(struct pmac_therm *sensor)
{
struct pmac_sens_le *list_entry;
list_entry = malloc(sizeof(struct pmac_sens_le), M_PMACTHERM,
M_ZERO | M_WAITOK);
list_entry->sensor = sensor;
list_entry->last_val = 0;
list_entry->critical_count = 0;
SLIST_INSERT_HEAD(&sensors, list_entry, entries);
}