PowerHAL: Adds the low power mode power hint.
Low Power Mode power hint caps the maximum frequency.
It also reduces the refresh rate by making service call to the
SurfaceFlinger.
In case of hot plugged cpu, the max frequency is set when the cpu is
hotplugged in, using uevent notification.
Change-Id: Id78fbd765b36785d8ecdfee26d6299b39cad2874
Signed-off-by: Ruchi Kandoi<kandoiruchi@google.com>
diff --git a/init.grouper.rc b/init.grouper.rc
index bdc92e3..0aaf9a3 100644
--- a/init.grouper.rc
+++ b/init.grouper.rc
@@ -258,6 +258,22 @@
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/max_boost
chown system system /sys/devices/system/cpu/cpufreq/interactive/sustain_load
chmod 0660 /sys/devices/system/cpu/cpufreq/interactive/sustain_load
+ chown system system /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
+ chmod 0660 /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
+ chown system system /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
+ chmod 0660 /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
+ chown system system /sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq
+ chmod 0660 /sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq
+ chown system system /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
+ chmod 0660 /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
+ chown system system /sys/devices/system/cpu/cpu2/cpufreq/scaling_min_freq
+ chmod 0660 /sys/devices/system/cpu/cpu2/cpufreq/scaling_min_freq
+ chown system system /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
+ chmod 0660 /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
+ chown system system /sys/devices/system/cpu/cpu3/cpufreq/scaling_min_freq
+ chmod 0660 /sys/devices/system/cpu/cpu3/cpufreq/scaling_min_freq
+ chown system system /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
+ chmod 0660 /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
# Default Read Ahead value for sdcards
write /sys/block/mmcblk0/queue/read_ahead_kb 2048
diff --git a/power/power.c b/power/power.c
index 687fe0b..29c5638 100644
--- a/power/power.c
+++ b/power/power.c
@@ -18,6 +18,13 @@
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
+#include <sys/socket.h>
+#include <cutils/uevent.h>
+#include <sys/poll.h>
+#include <pthread.h>
+#include <linux/netlink.h>
+#include <stdlib.h>
+#include <stdbool.h>
#define LOG_TAG "Grouper PowerHAL"
#include <utils/Log.h>
@@ -26,10 +33,36 @@
#include <hardware/power.h>
#define BOOST_PATH "/sys/devices/system/cpu/cpufreq/interactive/boost"
+#define UEVENT_MSG_LEN 1024
+#define TOTAL_CPUS 4
+#define RETRY_TIME_CHANGING_FREQ 20
+#define SLEEP_USEC_BETWN_RETRY 200
+#define LOW_POWER_MAX_FREQ "640000"
+#define LOW_POWER_MIN_FREQ "51000"
+#define NORMAL_MAX_FREQ "1300000"
+#define UEVENT_STRING "online@/devices/system/cpu/"
+
static int boost_fd = -1;
static int boost_warned;
-static void sysfs_write(char *path, char *s)
+static struct pollfd pfd;
+static char *cpu_path_min[] = {
+ "/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq",
+ "/sys/devices/system/cpu/cpu1/cpufreq/scaling_min_freq",
+ "/sys/devices/system/cpu/cpu2/cpufreq/scaling_min_freq",
+ "/sys/devices/system/cpu/cpu3/cpufreq/scaling_min_freq",
+};
+static char *cpu_path_max[] = {
+ "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq",
+ "/sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq",
+ "/sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq",
+ "/sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq",
+};
+static bool freq_set[TOTAL_CPUS];
+static bool low_power_mode = false;
+static pthread_mutex_t low_power_mode_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static int sysfs_write(char *path, char *s)
{
char buf[80];
int len;
@@ -38,19 +71,115 @@
if (fd < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error opening %s: %s\n", path, buf);
- return;
+ return -1;
}
len = write(fd, s, strlen(s));
if (len < 0) {
strerror_r(errno, buf, sizeof(buf));
ALOGE("Error writing to %s: %s\n", path, buf);
+ return -1;
}
close(fd);
+ return 0;
}
-static void grouper_power_init(struct power_module *module)
+static int uevent_event()
+{
+ char msg[UEVENT_MSG_LEN];
+ char *cp;
+ int n, cpu, ret, retry = RETRY_TIME_CHANGING_FREQ;
+
+ n = recv(pfd.fd, msg, UEVENT_MSG_LEN, MSG_DONTWAIT);
+ if (n <= 0) {
+ return -1;
+ }
+ if (n >= UEVENT_MSG_LEN) { /* overflow -- discard */
+ return -1;
+ }
+
+ cp = msg;
+
+ if (strstr(cp, UEVENT_STRING)) {
+ n = strlen(cp);
+ errno = 0;
+ cpu = strtol(cp + n - 1, NULL, 10);
+
+ if (errno == EINVAL || errno == ERANGE || cpu < 0 || cpu >= TOTAL_CPUS) {
+ return -1;
+ }
+
+ pthread_mutex_lock(&low_power_mode_lock);
+ if (low_power_mode && !freq_set[cpu]) {
+ while (retry) {
+ sysfs_write(cpu_path_min[cpu], LOW_POWER_MIN_FREQ);
+ ret = sysfs_write(cpu_path_max[cpu], LOW_POWER_MAX_FREQ);
+ if (!ret) {
+ freq_set[cpu] = true;
+ break;
+ }
+ usleep(SLEEP_USEC_BETWN_RETRY);
+ retry--;
+ }
+ } else if (!low_power_mode && freq_set[cpu]) {
+ while (retry) {
+ ret = sysfs_write(cpu_path_max[cpu], NORMAL_MAX_FREQ);
+ if (!ret) {
+ freq_set[cpu] = false;
+ break;
+ }
+ usleep(SLEEP_USEC_BETWN_RETRY);
+ retry--;
+ }
+ }
+ pthread_mutex_unlock(&low_power_mode_lock);
+ }
+ return 0;
+}
+
+void *thread_uevent(__attribute__((unused)) void *x)
+{
+ while (1) {
+ int nevents, ret;
+
+ nevents = poll(&pfd, 1, -1);
+
+ if (nevents == -1) {
+ if (errno == EINTR)
+ continue;
+ ALOGE("powerhal: thread_uevent: poll_wait failed\n");
+ break;
+ }
+ ret = uevent_event();
+ if (ret < 0)
+ ALOGE("Error processing the uevent event");
+ }
+ return NULL;
+}
+
+
+static void uevent_init()
+{
+ struct sockaddr_nl client;
+ pthread_t tid;
+ pfd.fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+
+ if (pfd.fd < 0) {
+ ALOGE("%s: failed to open: %s", __func__, strerror(errno));
+ return;
+ }
+ memset(&client, 0, sizeof(struct sockaddr_nl));
+ pthread_create(&tid, NULL, thread_uevent, NULL);
+ client.nl_family = AF_NETLINK;
+ client.nl_pid = tid;
+ client.nl_groups = -1;
+ pfd.events = POLLIN;
+ bind(pfd.fd, (void *)&client, sizeof(struct sockaddr_nl));
+ return;
+}
+
+static void grouper_power_init( __attribute__((unused)) struct power_module *module)
{
/*
* cpufreq interactive governor: timer 20ms, min sample 100ms,
@@ -67,9 +196,10 @@
"0");
sysfs_write("/sys/devices/system/cpu/cpufreq/interactive/input_boost",
"1");
+ uevent_init();
}
-static void grouper_power_set_interactive(struct power_module *module, int on)
+static void grouper_power_set_interactive( __attribute__((unused)) struct power_module *module, int on)
{
/*
* Lower maximum frequency when screen is off. CPU 0 and 1 share a
@@ -87,16 +217,42 @@
}
-static void grouper_power_hint(struct power_module *module, power_hint_t hint,
+static void grouper_power_hint(__attribute__((unused)) struct power_module *module, power_hint_t hint,
void *data)
{
char buf[80];
- int len;
+ int len, cpu, ret;
switch (hint) {
case POWER_HINT_VSYNC:
break;
+ case POWER_HINT_LOW_POWER:
+ pthread_mutex_lock(&low_power_mode_lock);
+ if (data) {
+ low_power_mode = true;
+ for (cpu = 0; cpu < TOTAL_CPUS; cpu++) {
+ sysfs_write(cpu_path_min[cpu], LOW_POWER_MIN_FREQ);
+ ret = sysfs_write(cpu_path_max[cpu], LOW_POWER_MAX_FREQ);
+ if (!ret) {
+ freq_set[cpu] = true;
+ }
+ }
+ // reduces the refresh rate
+ system("service call SurfaceFlinger 1016");
+ } else {
+ low_power_mode = false;
+ for (cpu = 0; cpu < TOTAL_CPUS; cpu++) {
+ ret = sysfs_write(cpu_path_max[cpu], NORMAL_MAX_FREQ);
+ if (!ret) {
+ freq_set[cpu] = false;
+ }
+ }
+ // restores the refresh rate
+ system("service call SurfaceFlinger 1017");
+ }
+ pthread_mutex_unlock(&low_power_mode_lock);
+ break;
default:
break;
}