linux-kernel - [PATCH] ACPI / PM: Do not reconfigure GPEs for suspend-to-idle

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Date:   Thu, 07 Dec 2017 03:27:51 +0100
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Mario Limonciello <mario.limonciello@...l.com>
Subject: [PATCH] ACPI / PM: Do not reconfigure GPEs for suspend-to-idle

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Currently, non-wakeup GPEs are disabled on suspend-to-idle
entry to avoid spurious wakeups, but that should not be strictly
necessary any more after commit 33e4f80ee69b (ACPI / PM: Ignore
spurious SCI wakeups from suspend-to-idle) which prevents spurious
GPE wakeups from resuming the system.  The only consequence of
leaving non-wakeup GPEs enabled may be more interrupt-related
activity while suspended, which is not ideal (more energy is
used if that happens), but it is not critical too.

On the other hand, this change allows Dells XPS13 9360 blacklisted by
commit 71630b7a832f (ACPI / PM: Blacklist Low Power S0 Idle _DSM for
Dell XPS13 9360) to use the power button for waking up from suspend-
to-idle and it helps at least one other older Dell system (the
wakeup button GPE on that one is not listed in _PRW for any
devices, so it is not regarded as a wakeup one and gets disabled
on suspend-to-idle entry today).

For the above reasons, leave GPE configuration as is over
suspend-to-idle on all systems.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/acpi/sleep.c |   11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Index: linux-pm/drivers/acpi/sleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/sleep.c
+++ linux-pm/drivers/acpi/sleep.c
@@ -951,15 +951,8 @@ static int acpi_s2idle_prepare(void)
 	if (lps0_device_handle) {
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
-	} else {
-		/*
-		 * The configuration of GPEs is changed here to avoid spurious
-		 * wakeups, but that should not be necessary if this is a
-		 * "low-power S0" platform and the low-power S0 _DSM is present.
-		 */
-		acpi_enable_all_wakeup_gpes();
-		acpi_os_wait_events_complete();
 	}
+
 	if (acpi_sci_irq_valid())
 		enable_irq_wake(acpi_sci_irq);

@@ -1005,8 +998,6 @@ static void acpi_s2idle_restore(void)
 	if (lps0_device_handle) {
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
 		acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
-	} else {
-		acpi_enable_all_runtime_gpes();
 	}
 }