[PATCH 4.4 193/210] ACPI / PM: Runtime resume devices when waking from hibernate

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lukas Wunner <lukas@xxxxxxxxx>

commit fbda4b38fa3995aa0777fe9cbbdcb223c6292083 upstream.

Commit 58a1fbbb2ee8 ("PM / PCI / ACPI: Kick devices that might have been
reset by firmware") added a runtime resume for devices that were runtime
suspended when the system entered suspend-to-RAM.

Briefly, the motivation was to ensure that devices did not remain in a
reset-power-on state after resume, potentially preventing deep SoC-wide
low-power states from being entered on idle.

Currently we're not doing the same when leaving suspend-to-disk and this
asymmetry is a problem if drivers rely on the automatic resume triggered
by pm_complete_with_resume_check(). Fix it.

Fixes: 58a1fbbb2ee8 (PM / PCI / ACPI: Kick devices that might have been reset by firmware)
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/acpi/sleep.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -714,6 +714,7 @@ static int acpi_hibernation_enter(void)
 
 static void acpi_hibernation_leave(void)
 {
+	pm_set_resume_via_firmware();
 	/*
 	 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
 	 * enable it here.