https://blog.csdn.net/mike8825/article/details/80423842
system/core/libsuspend/autosuspend.c
system/core/libsuspend/autosuspend_wakeup_count.c
kernel/kernel/power/main.c
上面的作用是对/sys/power/wakeup_count进行读写(涉及到变量combined_event_count，
可参考https://blog.csdn.net/mike8825/article/details/80422993)，如果所有的锁都已解锁，
则写"mem"到/sys/power/state进行休眠
kernel/kernel/power/main.c
dpm(Device power management),有几个dpm开头的函数，其作用是运行设备的电源管理函数
int dpm_suspend_start(pm_message_t state) { dpm_prepare(state); //prepare dpm_list dpm_suspend(state); //suspend dpm_prepared_list } int dpm_suspend_end(pm_message_t state) { dpm_suspend_late(state); //suspend_late dpm_suspended_list dpm_suspend_noirq(state); //suspend_noirq dpm_late_early_list } void dpm_resume_start(pm_message_t state) { dpm_resume_noirq(state); //resume_noirq dpm_resume_early(state); //resume_early } void dpm_resume_end(pm_message_t state) { dpm_resume(state); //resume dpm_complete(state);//complete }休眠prepare--->suspend--->suspend_late--->suspend_noirq
唤醒resume_noirq--->resume_early--->resume--->complete
struct dev_pm_ops { int (*prepare)(struct device *dev); void (*complete)(struct device *dev); int (*suspend)(struct device *dev); int (*resume)(struct device *dev); int (*freeze)(struct device *dev); int (*thaw)(struct device *dev); int (*poweroff)(struct device *dev); int (*restore)(struct device *dev); int (*suspend_late)(struct device *dev); int (*resume_early)(struct device *dev); int (*freeze_late)(struct device *dev); int (*thaw_early)(struct device *dev); int (*poweroff_late)(struct device *dev); int (*restore_early)(struct device *dev); int (*suspend_noirq)(struct device *dev); int (*resume_noirq)(struct device *dev); int (*freeze_noirq)(struct device *dev); int (*thaw_noirq)(struct device *dev); int (*poweroff_noirq)(struct device *dev); int (*restore_noirq)(struct device *dev); int (*runtime_suspend)(struct device *dev); int (*runtime_resume)(struct device *dev); int (*runtime_idle)(struct device *dev); };如
static const struct dev_pm_ops goodix_ts_dev_pm_ops = { .suspend = goodix_ts_suspend, .resume = goodix_ts_resume, };类dpm函数的作用是按顺序执行相关的电源函数
上面有个suspend_ops的指针(cpu休眠时的动作)，其定义在
kernel/drivers/cpuidle/lpm-levels.c
static int lpm_probe(struct platform_device *pdev) { suspend_set_ops(&lpm_suspend_ops); } static const struct platform_suspend_ops lpm_suspend_ops = { .enter = lpm_suspend_enter, .valid = suspend_valid_only_mem, .prepare_late = lpm_suspend_prepare, .wake = lpm_suspend_wake, };kernel/kernel/power/suspend.c
void suspend_set_ops(const struct platform_suspend_ops *ops) { suspend_ops = ops; }参考的内核打印如下
52.402471: <6> PM: suspend entry 1970-01-01 00:13:08.409503329 UTC 52.402486: <2> PM: Syncing filesystems ... done. 52.410354: <6> Error: returning -512 value 52.409207: <2> Freezing user space processes ... (elapsed 0.005 seconds) done. 52.415161: <2> Freezing remaining freezable tasks ... (elapsed 0.002 seconds) done. 52.418063: <2> Suspending console(s) (use no_console_suspend to debug) 52.451064: <6> PM: suspend of devices complete after 31.502 msecs 52.452177: <6> PM: late suspend of devices complete after 1.102 msecs 52.456733: <6> PM: noirq suspend of devices complete after 4.546 msecs 52.456743: <2> Disabling non-boot CPUs ... 52.458561: <6> migrate_irqs: 1510 callbacks suppressed 52.458564: <6> IRQ32 no longer affine to CPU3 52.458572: <6> IRQ33 no longer affine to CPU3 52.458579: <6> IRQ34 no longer affine to CPU3 52.458586: <6> IRQ36 no longer affine to CPU3 52.458593: <6> IRQ37 no longer affine to CPU3 52.458600: <6> IRQ38 no longer affine to CPU3 52.458608: <6> IRQ40 no longer affine to CPU3 52.458615: <6> IRQ41 no longer affine to CPU3 52.458622: <6> IRQ42 no longer affine to CPU3 52.458628: <6> IRQ43 no longer affine to CPU3 52.460298: <6> CPU3: shutdown 52.464728: <6> CPU4: shutdown 52.469291: <6> CPU5: shutdown 52.473567: <6> CPU6: shutdown 52.477904: <6> CPU7: shutdown 52.479231: <6> CPU0:msm_cpu_pm_enter_sleep mode:3 during suspend
文章来源: Android休眠的内核流程