以下是amlogic 905x android6.0的待机日志
假待机：
[ 79.159234@0] request_suspend_state: sleep (0->3) at 78988163869 (2015-01-01 00:01:24.258131660 UTC)
[ 79.162712@0] request_suspend_state,164,old_sleep=0,new_state=3
[ 79.168682@0] early_suspend: call handlers
[ 79.201103@0] avmute set to 2
[ 79.301870@0] hdmitx: system: HDMITX: early suspend
[ 79.301915@0] hdmitx: system: unmux DDC for gpio read edid
[ 79.308968@0]
[ 79.308968@0] vdac_enable: on:0,module_sel:8
[ 79.354569@0] fb: osd_suspended
[ 79.354611@0] sysled: early suspend ok
[ 79.355889@0] gxbb_pm: meson_system_early_suspend
[ 79.360544@0] early_suspend: sync
[ 80.080436@0] PM: suspend entry 2015-01-01 00:01:25.179274911 UTC
[ 80.080994@0] PM: Syncing filesystems ... done.
[ 80.110489@0] Freezing user space processes ... (elapsed 0.269 seconds) done.
[ 80.380308@0] Freezing remaining freezable tasks ... (elapsed 0.003 seconds) done.
[ 80.392719@0] RTL871X: suspend start
[ 80.424913@0] RTL871X: nolinked power save leave
[ 80.436464@0] RTL871X: rtw_cmd_thread(wlan0) stop_req:1, break
[ 80.445590@0] RTL871X: rtw_dev_unload: driver not in IPS
[ 80.476912@0] RTL871X: rtw_dev_unload: driver not in IPS
[ 80.478154@0] RTL871X: rtw suspend success in 80 ms
[ 80.614705@0] aml_snd_card: enter aml_suspend_pre
[ 80.614889@0] aml_snd_card: no audio pin_ctrl to suspend
[ 80.630767@0] aml_T9015_audio_suspend!
[ 80.630944@0] aml_snd_card: enter aml_suspend_post
[ 80.634393@0] meson_uart c11084c0.serial: pull up rts
[ 80.639082@0] amvecm: suspend module
[ 80.642597@0] DI: di: di_suspend
[ 80.646704@0] sysled: module suspend ok
[ 80.650166@0] PM: suspend of devices complete after 259.894 msecs
[ 80.655553@0] gxbb_pm: enter meson_pm_prepare!
[ 80.665042@0] PM: late suspend of devices complete after 5.337 msecs
[ 80.682488@0] PM: noirq suspend of devices complete after 16.474 msecs
[ 80.683457@0] Disabling non-boot CPUs ...
[ 80.687612@0] gxbb_pm: enter meson_pm_suspend!
[ 80.687612@0] gxbb_pm: late_suspend: call handlers
[ 80.687612@0] gxbb_pm: late_suspend: sync
bl30 get wakeup sources!
process command 00000006
bl30 enter suspend!
cpu clk suspend rate 100000000
suspend_counter: 1
Enter ddr suspend
first time suspend
ddr suspend time: 1886us
store restore gp0 pll
process command 00000001
CEC cfg:0x002f
set vddee to 0x035cmv
089 kern log_addr:0x04
rx stat:00, tx stat:00
ping_cec_ll_tx:TX_ERROR
Set cec log_addr:0x04, ADDR0:14
真待机：
[ 68.214993@1] BT_RADIO going: off
[ 68.215020@1] BCM_BT: going OFF
[ 68.442588@0] BT_RADIO going: on
[ 68.442752@0] BCM_BT: going ON
[ 68.687745@1] aml_spdif_dai: aml_hw_iec958_init,runtime->rate=48000, same source mode(1)
[ 68.690825@1] aml_spdif_dai: share the same clock
[ 68.694954@1] aml_spdif_dai: iec958 mode PCM16
[ 68.699346@1] aml_audio_hw: IEC958 16bit
[ 68.703504@1] hdmitx: audio: aout notify rate 48000
[ 68.708042@1] hdmitx: audio: aout notify size 16
[ 68.712906@1] hdmitx: audio: no update
[ 68.716294@1] aml_snd_m8_card aml_m8_snd.46: i2s/958 same source
[ 68.751379@1] aml_snd_m8_card aml_m8_snd.46: I2S playback enable
[ 68.751759@1] aml_snd_m8_card aml_m8_snd.46: IEC958 playback enable
[ 69.368257@0] meson_uart c11084c0.serial: ttyS1 use xtal(8M) 24000000 change 1500000 to 1500000
[ 69.373019@0] meson_uart c11084c0.serial: ttyS1 use xtal(8M) 24000000 change 1500000 to 1500000
[ 69.380607@0] meson_uart c11084c0.serial: ttyS1 use xtal(8M) 24000000 change 1500000 to 115200
[ 69.910159@0] meson_uart c11084c0.serial: ttyS1 use xtal(8M) 24000000 change 115200 to 1500000
[ 69.914035@0] meson_uart c11084c0.serial: ttyS1 use xtal(8M) 24000000 change 1500000 to 1500000
[ 70.874014@0] SysRq : Emergency Remount R/O
[ 70.880471@1] EXT4-fs (mmcblk0p14): re-mounted. Opts: (null)
[ 70.883091@1] EXT4-fs (mmcblk0p3): re-mounted. Opts: (null)
[ 70.889695@1] EXT4-fs (mmcblk0p8): re-mounted. Opts: (null)
[ 70.891972@1] EXT4-fs (zram0): re-mounted. Opts: (null)
[ 70.904583@1] Emergency Remount complete
[ 70.974799@1] avmute set to 2
[ 71.768553@0] aml_snd_m8_card aml_m8_snd.46: I2S playback disable
[ 71.769016@0] aml_snd_m8_card aml_m8_snd.46: IEC958 playback disable
[ 71.775430@0] aml_spdif_dai: share the same clock
[ 71.779982@0] aml_audio_hw: IEC958 16bit
[ 71.784033@0] hdmitx: audio: aout notify rate 48000
[ 71.788698@0] hdmitx: audio: aout notify size 16
[ 71.793337@0] hdmitx: audio: no update
[ 72.101818@0] aml_snd_card: no audio pin_ctrl to shutdown
[ 72.102215@0] sysled: module shutdown ok
[ 72.105939@0] reboot: Power down
INFO: PSCI Affinity Map:
INFO: AffInst: Level 0, MPID 0x0, State ON
INFO: AffInst: Level 0, MPID 0x1, State ON
INFO: AffInst: Level 0, MPID 0x2, State OFF
INFO: AffInst: Level 0, MPID 0x3, State OFF
bl31 reboot reason: 0x108
bl31 reboot reason: 0x108
system cmd 0.
bl30 get wakeup sources!
process command 00000006
bl30 enter suspend!
cpu clk suspend rate 1000000000
suspend_counter: 1
Enter ddr suspend
first time suspend
ddr suspend time: 1886us
store restore gp0 pll
process command 00000001
CEC cfg:0x002f
set vddee to 0x035cmv
089 kern log_addr:0x04
rx stat:00, tx stat:00
ping_cec_ll_tx:TX_ERROR
Set cec log_addr:0x04, ADDR0:14
android上层通过设置环境变量去关机
public static void lowLevelShutdown() {
SystemProperties.set("sys.powerctl", "shutdown");
}直接触发init.rc去执行
on property:sys.powerctl=*
powerctl ${sys.powerctl}./code/system/core/init/keywords.h:80: KEYWORD(powerctl, COMMAND, 1, do_powerctl)
int do_powerctl(int nargs, char **args);
./code/system/core/init/builtins.cpp:581:int do_powerctl(int nargs, char **args)int do_powerctl(int nargs, char **args)
{
char command[PROP_VALUE_MAX];
int res;
int len = 0;
int cmd = 0;
const char *reboot_target;
res = expand_props(command, args[1], sizeof(command));
if (res) {
ERROR("powerctl: cannot expand '%s'\n", args[1]);
return -EINVAL;
}
if (strncmp(command, "shutdown", 8) == 0) {
cmd = ANDROID_RB_POWEROFF;
len = 8;
} else if (strncmp(command, "reboot", 6) == 0) {
cmd = ANDROID_RB_RESTART2;
len = 6;
} else {
ERROR("powerctl: unrecognized command '%s'\n", command);
return -EINVAL;
}
if (command[len] == ',') {
reboot_target = &command[len + 1];
} else if (command[len] == '\0') {
reboot_target = "";
} else {
ERROR("powerctl: unrecognized reboot target '%s'\n", &command[len]);
return -EINVAL;
}
return android_reboot(cmd, 0, reboot_target);
}do_powerctl根据cmd标记flags
if (strncmp(command, "shutdown", 8) == 0) {
cmd = ANDROID_RB_POWEROFF;
len = 8;
} else if (strncmp(command, "reboot", 6) == 0) {
cmd = ANDROID_RB_RESTART2;
len = 6;用android_reboot(cmd, 0, reboot_target);执行命令
其中
#define ANDROID_RB_RESTART 0xDEAD0001
#define ANDROID_RB_POWEROFF 0xDEAD0002
#define ANDROID_RB_RESTART2 0xDEAD0003int android_reboot(int cmd, int flags UNUSED, const char *arg)
{
int ret;
sync();
remount_ro();
switch (cmd) {
case ANDROID_RB_RESTART:
ret = reboot(RB_AUTOBOOT);
break;
case ANDROID_RB_POWEROFF:
ret = reboot(RB_POWER_OFF);
break;
case ANDROID_RB_RESTART2:
ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
LINUX_REBOOT_CMD_RESTART2, arg);
break;
default:
ret = -1;
}
return ret;
}./bionic/libc/bionic/reboot.cpp:35
extern "C" int __reboot(int, int, int, void*);
int reboot(int mode) {
return __reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, mode, NULL);
}./bionic/libc/arch-arm64/syscalls/__reboot.S
/* Generated by gensyscalls.py. Do not edit. */
#include <private/bionic_asm.h>
ENTRY(__reboot)
mov x8, __NR_reboot
svc #0
cmn x0, #(MAX_ERRNO + 1)
cneg x0, x0, hi
b.hi __set_errno_internal
ret
END(__reboot)
.hidden __reboot
=》最后会进入Kernel
如
./prebuilts/ndk/8/platforms/android-9/arch-arm/usr/include/sys/reboot.h:42:#define RB_POWER_OFF LINUX_REBOOT_CMD_POWER_OFF
则进入内核的kernel/reboot.c
SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
void __user *, arg)
{
case LINUX_REBOOT_CMD_POWER_OFF:
kernel_power_off();
do_exit(0);
break;
void kernel_power_off(void)
{
kernel_shutdown_prepare(SYSTEM_POWER_OFF);
if (pm_power_off_prepare)
pm_power_off_prepare();
migrate_to_reboot_cpu();
syscore_shutdown();
pr_emerg("Power down\n");
kmsg_dump(KMSG_DUMP_POWEROFF);
machine_power_off();
}
EXPORT_SYMBOL_GPL(kernel_power_off);Process.c (arch\arm64\kernel):void machine_power_off(void)
void machine_power_off(void)
{
local_irq_disable();
machine_shutdown();
if (pm_power_off) 关电源
pm_power_off();
}
关闭多核
void machine_shutdown(void)
{
#ifdef CONFIG_SMP
smp_send_stop();
#endif
}
void smp_send_stop(void)
{
unsigned long timeout;
if (num_online_cpus() > 1) {
cpumask_t mask;
cpumask_copy(&mask, cpu_online_mask);
cpu_clear(smp_processor_id(), mask);
smp_cross_call(&mask, IPI_CPU_STOP);
}
/* Wait up to one second for other CPUs to stop */
timeout = USEC_PER_SEC;
while (num_online_cpus() > 1 && timeout--)
udelay(1);
if (num_online_cpus() > 1)
pr_warning("SMP: failed to stop secondary CPUs\n");
}函数指针pm_power_off是与平台相关的指针， 只是一个函数指针，而且做了全局操作，整个kernel都可以调用它，amlogic平台是如下方法设置的
./common/drivers/amlogic/reset/gxbb_poweroff.c:152: pm_power_off = do_aml_poweroff;
static void do_aml_poweroff(void)
{
/* TODO: Add poweroff capability */
__invoke_psci_fn_smc(0x82000042, 1, 0, 0);
__invoke_psci_fn_smc(psci_function_id_poweroff,
0, 0, 0);
}
即最后设置寄存器:
static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
register long x0 asm("x0") = function_id;
register long x1 asm("x1") = arg0;
register long x2 asm("x2") = arg1;
register long x3 asm("x3") = arg2;
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"smc #0\n"
: "+r" (x0)
: "r" (x1), "r" (x2), "r" (x3));
return function_id;
}系统没有wake_lock时，以下timer会检测执行回调：
static void suspend(struct work_struct *work)
{
int ret;
int entry_event_num;
struct timespec ts_entry, ts_exit;
if (has_wake_lock(WAKE_LOCK_SUSPEND)) {
if (debug_mask & DEBUG_SUSPEND)
pr_info("suspend: abort suspend\n");
return;
}
entry_event_num = current_event_num;
if (debug_mask & DEBUG_SUSPEND)
pr_info("suspend: sys_sync...");
sys_sync();
if (debug_mask & DEBUG_SUSPEND)
pr_info("done.\n");
if (debug_mask & DEBUG_SUSPEND)
pr_info("suspend: enter suspend\n");
getnstimeofday(&ts_entry);
ret = pm_suspend(requested_suspend_state);
getnstimeofday(&ts_exit);
if (debug_mask & DEBUG_EXIT_SUSPEND) {
struct rtc_time tm;
rtc_time_to_tm(ts_exit.tv_sec, &tm);
pr_info("suspend: exit suspend, ret = %d (%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
ret,
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, ts_exit.tv_nsec);
}
if (ts_exit.tv_sec - ts_entry.tv_sec <= 1) {
++suspend_short_count;
if (suspend_short_count == SUSPEND_BACKOFF_THRESHOLD) {
suspend_backoff();
suspend_short_count = 0;
}
} else {
suspend_short_count = 0;
}
if (current_event_num == entry_event_num) {
if (debug_mask & DEBUG_SUSPEND)
pr_info("suspend: pm_suspend returned with no event\n");
}
wake_lock_timeout(&unknown_wakeup, 5 * HZ);
}
static DECLARE_WORK(suspend_work, suspend);
static void expire_wake_locks(unsigned long data)
{
long has_lock;
unsigned long irqflags;
if (debug_mask & DEBUG_EXPIRE)
pr_info("expire_wake_locks: start\n");
spin_lock_irqsave(&list_lock, irqflags);
if (debug_mask & DEBUG_SUSPEND)
print_active_locks(WAKE_LOCK_SUSPEND);
has_lock = has_wake_lock_locked(WAKE_LOCK_SUSPEND);
if (debug_mask & DEBUG_EXPIRE)
pr_info("expire_wake_locks: done, has_lock %ld\n", has_lock);
if (has_lock == 0)
queue_work(suspend_work_queue, &suspend_work);
spin_unlock_irqrestore(&list_lock, irqflags);
}
static DEFINE_TIMER(expire_timer, expire_wake_locks, 0, 0);
该timer会在多个地方用到，在激活锁的函数中注册用于超时锁到期后检测系统的有效锁状态，如果系统不存在有效锁了则启动suspend进程回调pm_suspend。上层修改的对应的设备节点之后
正常时是
root@p212:/sys/power # cat wake_unlock
KeyEvents PowerManagerService.WakeLocks
root@p212:/sys/power # cat wake_lock
PowerManagerService.Display
root@p212:/sys/power # cat state
mem disk
root@p212:/sys/power # const char * const OLD_PATHS[] = {
"/sys/android_power/acquire_partial_wake_lock",
"/sys/android_power/release_wake_lock",
};
const char * const NEW_PATHS[] = {
"/sys/power/wake_lock",
"/sys/power/wake_unlock",
};执行以下代码：
static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
suspend_state_t state;
int error;
error = pm_autosleep_lock();
if (error)
return error;
if (pm_autosleep_state() > PM_SUSPEND_ON) {
error = -EBUSY;
goto out;
}
state = decode_state(buf, n);
if (state < PM_SUSPEND_MAX) {
#ifdef CONFIG_EARLYSUSPEND
if (state == PM_SUSPEND_ON || state == PM_SUSPEND_MEM) {
error = 0;
request_suspend_state(state);
}
#else
error = pm_suspend(state);
#endif
}
else if (state == PM_SUSPEND_MAX)
error = hibernate();
else
error = -EINVAL;
out:
pm_autosleep_unlock();
return error ? error : n;
}重点执行这个func request_suspend_state
void request_suspend_state(suspend_state_t new_state)
{
unsigned long irqflags;
int old_sleep;
spin_lock_irqsave(&state_lock, irqflags);
old_sleep = state & SUSPEND_REQUESTED;
if (debug_mask & DEBUG_USER_STATE) {
struct timespec ts;
struct rtc_time tm;
getnstimeofday(&ts);
rtc_time_to_tm(ts.tv_sec, &tm);
pr_info("request_suspend_state: %s (%d->%d) at %lld "
"(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
new_state != PM_SUSPEND_ON ? "sleep" : "wakeup",
requested_suspend_state, new_state,
ktime_to_ns(ktime_get()),
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
}
pr_info("%s,%d,old_sleep=%d,new_state=%d\n", __func__, __LINE__,
old_sleep, new_state);
if (!old_sleep && new_state != PM_SUSPEND_ON) {
state |= SUSPEND_REQUESTED;
queue_work(suspend_work_queue, &early_suspend_work);
} else if (old_sleep && new_state == PM_SUSPEND_ON) {
state &= ~SUSPEND_REQUESTED;
wake_lock(&main_wake_lock);
queue_work(suspend_work_queue, &late_resume_work);
}
requested_suspend_state = new_state;
spin_unlock_irqrestore(&state_lock, irqflags);
}于是我们就看到了以上打印
pr_info("request_suspend_state: %s (%d->%d) at %lld "
"(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
new_state != PM_SUSPEND_ON ? "sleep" : "wakeup",
requested_suspend_state, new_state,
ktime_to_ns(ktime_get()),
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec) pr_info("%s,%d,old_sleep=%d,new_state=%d\n", __func__, __LINE__,
old_sleep, new_state);[ 735.994473@0] request_suspend_state: sleep (0->3) at 735823580141 (2015-01-01 00:34:28.725320516 UTC)
[ 735.998034@0] request_suspend_state,164,old_sleep=0,new_state=3表示进下如下流程：
if (!old_sleep && new_state != PM_SUSPEND_ON) {
state |= SUSPEND_REQUESTED;
queue_work(suspend_work_queue, &early_suspend_work);
} 修改标记位，执行工作队列回调
queue_work(suspend_work_queue, &early_suspend_work);
static void early_suspend(struct work_struct *work)
{
struct early_suspend *pos;
unsigned long irqflags;
int abort = 0;
mutex_lock(&early_suspend_lock);
spin_lock_irqsave(&state_lock, irqflags);
if (state == SUSPEND_REQUESTED)
state |= SUSPENDED;
else
abort = 1;
spin_unlock_irqrestore(&state_lock, irqflags);
if (abort) {
if (debug_mask & DEBUG_SUSPEND)
pr_info("early_suspend: abort, state %d\n", state);
mutex_unlock(&early_suspend_lock);
goto abort;
}
if (debug_mask & DEBUG_SUSPEND)
pr_info("early_suspend: call handlers\n");
list_for_each_entry(pos, &early_suspend_handlers, link) {
if (pos->suspend != NULL)
pos->suspend(pos);
}
mutex_unlock(&early_suspend_lock);
if (debug_mask & DEBUG_SUSPEND)
pr_info("early_suspend: sync\n");
sys_sync();
abort:
spin_lock_irqsave(&state_lock, irqflags);
if (state == SUSPEND_REQUESTED_AND_SUSPENDED)
wake_unlock(&main_wake_lock);
spin_unlock_irqrestore(&state_lock, irqflags);
}接着走
if (debug_mask & DEBUG_SUSPEND)
pr_info("early_suspend: call handlers\n");
list_for_each_entry(pos, &early_suspend_handlers, link) {
if (pos->suspend != NULL)
pos->suspend(pos);
}执行注册在early_suspend_handlers的所有回调函数
之后释放锁
if (debug_mask & DEBUG_SUSPEND)
pr_info("early_suspend: sync\n");
sys_sync();