Commit 0c4cae1b authored by Chris Feng's avatar Chris Feng Committed by Rafael J. Wysocki
Browse files

PM: hibernate: Avoid missing wakeup events during hibernation 



Wakeup events that occur in the hibernation process's
hibernation_platform_enter() cannot wake up the system. Although the
current hibernation framework will execute part of the recovery process
after a wakeup event occurs, it ultimately performs a shutdown operation
because the system does not check the return value of
hibernation_platform_enter(). In short, if a wakeup event occurs before
putting the system into the final low-power state, it will be missed.

To solve this problem, check the return value of
hibernation_platform_enter(). When it returns -EAGAIN or -EBUSY (indicate
the occurrence of a wakeup event), execute the hibernation recovery
process, discard the previously saved image, and ultimately return to the
working state.

Signed-off-by: default avatarChris Feng <chris.feng@mediatek.com>
[ rjw: Rephrase the message printed when going back to the working state ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4ac934b1

kernel/power/hibernate.c

+8 −2
Original line number Diff line number Diff line
@@ -642,9 +642,9 @@ int hibernation_platform_enter(void) 
 */

static void power_down(void)

{

#ifdef CONFIG_SUSPEND

	int error;



#ifdef CONFIG_SUSPEND

	if (hibernation_mode == HIBERNATION_SUSPEND) {

		error = suspend_devices_and_enter(mem_sleep_current);

		if (error) {
@@ -667,7 +667,13 @@ static void power_down(void) 
		kernel_restart(NULL);

		break;

	case HIBERNATION_PLATFORM:

		hibernation_platform_enter();

		error = hibernation_platform_enter();

		if (error == -EAGAIN || error == -EBUSY) {

			swsusp_unmark();

			events_check_enabled = false;

			pr_info("Wakeup event detected during hibernation, rolling back.\n");

			return;

		}

		fallthrough;

	case HIBERNATION_SHUTDOWN:

		if (kernel_can_power_off())

kernel/power/power.h

+2 −0
Original line number Diff line number Diff line
@@ -175,6 +175,8 @@ extern int swsusp_write(unsigned int flags); 
void swsusp_close(void);

#ifdef CONFIG_SUSPEND

extern int swsusp_unmark(void);

#else

static inline int swsusp_unmark(void) { return 0; }

#endif



struct __kernel_old_timeval;