ACPI: PM: Set enable_for_wake for wakeup GPEs during suspend-to-idle

I noticed that recently multiple systems (chromebooks) couldn't wake
from S0ix using LID or Keyboard after updating to a newer kernel. I
bisected and it turned up commit f941d3e4 ("ACPI: EC / PM: Disable
non-wakeup GPEs for suspend-to-idle"). I checked that the issue got
fixed if that commit was reverted.

I debugged and found that although PNP0C0D:00 (representing the LID)
is wake capable and should wakeup the system per the code in
acpi_wakeup_gpe_init() and in drivers/acpi/button.c:

localhost /sys # cat /proc/acpi/wakeup
Device  S-state   Status   Sysfs node
LID0      S4    *enabled   platform:PNP0C0D:00
CREC      S5    *disabled  platform:GOOG0004:00
                *disabled  platform:cros-ec-dev.1.auto
                *disabled  platform:cros-ec-accel.0
                *disabled  platform:cros-ec-accel.1
                *disabled  platform:cros-ec-gyro.0
                *disabled  platform:cros-ec-ring.0
                *disabled  platform:cros-usbpd-charger.2.auto
                *disabled  platform:cros-usbpd-logger.3.auto
D015      S3    *enabled   i2c:i2c-ELAN0000:00
PENH      S3    *enabled   platform:PRP0001:00
XHCI      S3    *enabled   pci:0000:00:14.0
GLAN      S4    *disabled
WIFI      S3    *disabled  pci:0000:00:14.3
localhost /sys #

On debugging, I found that its corresponding GPE is not being enabled.
The particular GPE's "gpe_register_info->enable_for_wake" does not
have any bits set when acpi_enable_all_wakeup_gpes() comes around to
use it. I looked at code and could not find any other code path that
should set the bits in "enable_for_wake" bitmask for the wake enabled
devices for s2idle.  [I do see that it happens for S3 in
acpi_sleep_prepare()].

Thus I used the same call to enable the GPEs for wake enabled devices,
and verified that this fixes the regression I was seeing on multiple
of my devices.

[ rjw: The problem is that commit f941d3e4 ("ACPI: EC / PM:
  Disable non-wakeup GPEs for suspend-to-idle") forgot to add
  the acpi_enable_wakeup_devices() call for s2idle along with
  acpi_enable_all_wakeup_gpes(). ]

Fixes: f941d3e4 ("ACPI: EC / PM: Disable non-wakeup GPEs for suspend-to-idle")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203579Signed-off-by: Rajat Jain <rajatja@google.com>
[ rjw: Subject & changelog ]
Cc: 5.0+ <stable@vger.kernel.org> # 5.0+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/sleep.c

@@ -977,6 +977,8 @@ static int acpi_s2idle_prepare(void)
 	if (acpi_sci_irq_valid())
 		enable_irq_wake(acpi_sci_irq);
 
+	acpi_enable_wakeup_devices(ACPI_STATE_S0);
+
 	/* Change the configuration of GPEs to avoid spurious wakeup. */
 	acpi_enable_all_wakeup_gpes();
 	acpi_os_wait_events_complete();
@@ -1027,6 +1029,8 @@ static void acpi_s2idle_restore(void)
 {
 	acpi_enable_all_runtime_gpes();
 
+	acpi_disable_wakeup_devices(ACPI_STATE_S0);
+
 	if (acpi_sci_irq_valid())
 		disable_irq_wake(acpi_sci_irq);