[PATCH 1/2] ACPI / PM: Use register_reboot_notifier() instead of pm_power_off_prepare

From: Baolin Wang
Date: Wed Mar 21 2018 - 07:30:49 EST


We can register one notifier through register_reboot_notifier() function to
prepare to power off the system, then we can remove the 'pm_power_off_prepare'
hook in following patch.

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
---
Note: Please help to review carefully, since I have no platform to test
this conversion.

I saw there is another reboot notifier in this driver, I am not sure the
orders between them. I can change the priority of notifier to keep their
orders if it is necessary.
---
drivers/acpi/sleep.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index 46cde091..b3de894 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -1229,14 +1229,24 @@ static void acpi_sleep_hibernate_setup(void)
static inline void acpi_sleep_hibernate_setup(void) {}
#endif /* !CONFIG_HIBERNATION */

-static void acpi_power_off_prepare(void)
+static int acpi_reboot_notify(struct notifier_block *this, unsigned long code,
+ void *x)
{
- /* Prepare to power off the system */
- acpi_sleep_prepare(ACPI_STATE_S5);
- acpi_disable_all_gpes();
- acpi_os_wait_events_complete();
+ if (code == SYSTEM_POWER_OFF) {
+ /* Prepare to power off the system */
+ acpi_sleep_prepare(ACPI_STATE_S5);
+ acpi_disable_all_gpes();
+ acpi_os_wait_events_complete();
+ }
+
+ return NOTIFY_DONE;
}

+static struct notifier_block acpi_reboot_notifier = {
+ .notifier_call = acpi_reboot_notify,
+ .priority = 0,
+};
+
static void acpi_power_off(void)
{
/* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
@@ -1261,7 +1271,7 @@ int __init acpi_sleep_init(void)

if (acpi_sleep_state_supported(ACPI_STATE_S5)) {
sleep_states[ACPI_STATE_S5] = 1;
- pm_power_off_prepare = acpi_power_off_prepare;
+ register_reboot_notifier(&acpi_reboot_notifier);
pm_power_off = acpi_power_off;
} else {
acpi_no_s5 = true;
--
1.7.9.5