[PATCH] ACPI: button: Install notifier for system events as well

[Mario Limonciello <superm1@kernel.org>]

From: Mario Limonciello <mario.limonciello@amd.com>

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: Yijun Shen <Yijun.Shen@dell.com>
Tested-by: Richard 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: Mario Limonciello <mario.limonciello@amd.com>
---
 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 7773e6b860e73..61701c646e92f 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -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"
@@ -443,11 +444,16 @@ 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;
-	}
+	};
 
 	acpi_pm_wakeup_event(&device->dev);
 
@@ -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;
 	}
-- 
2.43.0