[RESEND PATCH] ACPICA: Enable sleep button on ACPI legacy wake

[Anchal Agarwal]

Currently we do not see sleep_enable bit set after guest resumes
from hibernation. Hibernation is triggered in guest on receiving
a sleep trigger from the hypervisor(S4 state). We see that power
button is enabled on wake up from S4 state however sleep button
isn't. This causes subsequent invocation of sleep state to fail
in the guest. Any environment  going through acpi_hw_legacy_wake()
won't have sleep button enabled.

Signed-off-by: Anchal Agarwal <anchalag@xxxxxxxxxx>
Reviewed-by: Balbir Singh <sblbir@xxxxxxxxxx>
Reviewed-by: Frank van der Linden <fllinden@xxxxxxxxxx>
---
 drivers/acpi/acpica/hwsleep.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index b62db8ec446f..a176c7802760 100644
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -300,6 +300,17 @@ acpi_status acpi_hw_legacy_wake(u8 sleep_state)
 				    [ACPI_EVENT_POWER_BUTTON].
 				    status_register_id, ACPI_CLEAR_STATUS);
 
+	/* Enable sleep button */
+	(void)
+	      acpi_write_bit_register(acpi_gbl_fixed_event_info
+				      [ACPI_EVENT_SLEEP_BUTTON].
+				      enable_register_id, ACPI_ENABLE_EVENT);
+
+	(void)
+	      acpi_write_bit_register(acpi_gbl_fixed_event_info
+				      [ACPI_EVENT_SLEEP_BUTTON].
+				      status_register_id, ACPI_CLEAR_STATUS);
+
 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
 	return_ACPI_STATUS(status);
 }