[PATCH 2/4] ACPI: button: Cancel hibernation if button is pressed during hibernation

[Muhammad Usama Anjum]

acpi_pm_wakeup_event() is called from acpi_button_notify() which is
called when power button is pressed. The system is worken up from s2idle
in this case by setting hard parameter to pm_wakeup_dev_event().

Call acpi_pm_wakeup_event() if power button is pressed and hibernation
is in progress. Set the hard parameter such that pm_system_wakeup()
gets called which increments pm_abort_suspend counter. The explicit call
to acpi_pm_wakeup_event() is necessary as ACPI button device has the
wakeup source. Hence call to input_report_key() with input device
doesn't call pm_system_wakeup() as it doesn't have wakeup source
registered.

Hence hibernation would be cancelled as in hibernation path, this counter
is checked if it should be aborted.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
---
Changes since RFC:
- Use pm_sleep_transition_in_progress()
- Update descriptin why explicit call to acpi_pm_wakeup_event() is
  necessary
---
 drivers/acpi/button.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 3c6dd9b4ba0ad..e4be5c763edaf 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -20,6 +20,7 @@
 #include <linux/acpi.h>
 #include <linux/dmi.h>
 #include <acpi/button.h>
+#include <linux/suspend.h>
 
 #define ACPI_BUTTON_CLASS		"button"
 #define ACPI_BUTTON_FILE_STATE		"state"
@@ -458,11 +459,16 @@ static void acpi_button_notify(acpi_handle handle, u32 event, void *data)
 	acpi_pm_wakeup_event(&device->dev);
 
 	button = acpi_driver_data(device);
-	if (button->suspended || event == ACPI_BUTTON_NOTIFY_WAKE)
-		return;
-
 	input = button->input;
 	keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;
+	if (event == ACPI_BUTTON_NOTIFY_STATUS && keycode == KEY_POWER &&
+	    pm_sleep_transition_in_progress()) {
+		pm_wakeup_dev_event(&device->dev, 0, true);
+		return;
+	}
+
+	if (button->suspended || event == ACPI_BUTTON_NOTIFY_WAKE)
+		return;
 
 	input_report_key(input, keycode, 1);
 	input_sync(input);
-- 
2.47.3