Commit a7e23ec1 authored by Mario Limonciello's avatar Mario Limonciello Committed by Rafael J. Wysocki
Browse files

ACPI: button: Install notifier for system events as well 



On some systems when the system is put to sleep pressing the ACPI power
button will cause the EC SCI to try to wake the system by a Notify(DEV, 0x2)
with an intention to wake the system up from suspend.

This behavior matches the ACPI specification in ACPI 6.4 section
4.8.3.1.1.2 which describes that the AML handler would generate a Notify()
with a code of 0x2 to indicate it was responsible for waking the system.

This currently doesn't work because acpi_button_add() only configured
`ACPI_DEVICE_NOTIFY` which means that device handler notifications
0x80 through 0xFF are handled.

To fix the wakeups on such systems, adjust the ACPI button handler to
use `ACPI_ALL_NOTIFY` which will handle all events 0x00 through 0x7F.

Reported-by: default avatarYijun Shen <Yijun.Shen@dell.com>
Tested-by: default avatarRichard Gong <Richard.Gong@amd.com>
Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/04_ACPI_Hardware_Specification/ACPI_Hardware_Specification.html?highlight=0x2#control-method-power-button


Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Tested-by: default avatarYijun Shen <Yijun_Shen@Dell.com>
Link: https://patch.msgid.link/20250303212719.4153485-1-superm1@kernel.org


[ rjw: Removed uneeded semicolon ]
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7eb17214

drivers/acpi/button.c

+8 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#define ACPI_BUTTON_CLASS		"button"

#define ACPI_BUTTON_FILE_STATE		"state"

#define ACPI_BUTTON_TYPE_UNKNOWN	0x00

#define ACPI_BUTTON_NOTIFY_WAKE		0x02

#define ACPI_BUTTON_NOTIFY_STATUS	0x80



#define ACPI_BUTTON_SUBCLASS_POWER	"power"
@@ -443,7 +444,12 @@ static void acpi_button_notify(acpi_handle handle, u32 event, void *data) 
	struct input_dev *input;

	int keycode;



	if (event != ACPI_BUTTON_NOTIFY_STATUS) {

	switch (event) {

	case ACPI_BUTTON_NOTIFY_STATUS:

		break;

	case ACPI_BUTTON_NOTIFY_WAKE:

		break;

	default:

		acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",

				  event);

		return;
@@ -629,7 +635,7 @@ static int acpi_button_add(struct acpi_device *device) 
		break;

	default:

		status = acpi_install_notify_handler(device->handle,

						     ACPI_DEVICE_NOTIFY, handler,

						     ACPI_ALL_NOTIFY, handler,

						     device);

		break;

	}