[PATCH] ACPI: Delay turning off unused resources after suspend till acpi_pm_end()

[Hans de Goede <hdegoede@redhat.com>]

Commit 660b1113e0f3 ("ACPI / PM: Fix consistency check for power resources
during resume") introduced a check for ACPI power resources which have
been turned on by the BIOS during suspend and turns these back off again.

This is causing problems on a Dell Venue Pro 11 7130 (i5-4300Y) it causes
the following messages to show up in dmesg:

[  131.014605] ACPI: Waking up from system sleep state S3
[  131.150271] acpi LNXPOWER:07: Turning OFF
[  131.150323] acpi LNXPOWER:06: Turning OFF
[  131.150911] acpi LNXPOWER:00: Turning OFF
[  131.169014] ACPI : EC: interrupt unblocked
[  131.181811] xhci_hcd 0000:00:14.0: System wakeup disabled by ACPI
[  133.535728] pci_raw_set_power_state: 76 callbacks suppressed
[  133.535735] iwlwifi 0000:01:00.0: Refused to change power state,
               currently in D3
[  133.597672] PM: noirq resume of devices complete after 2428.891 msecs

Followed by a bunch of iwlwifi errors later on and the pcie device
dropping from the bus (acpiphp thinks it has been unplugged).

Disabling the turning off of unused power resources fixes this. Instead
of adding a quirk for this system, this commit fixes this by moving the
disabling of unused power resources to later in the resume sequence
when the iwlwifi card has been moved out of D3 so the ref_count for
its power resource no longer is 0.

This new behavior seems to match the intend of the original commit which
commit-msg says: "which means that no devices are going to need them
any time soon) and we should turn them off".

This also avoids power resources which we need when bringing devices out
of D3 from getting bounced off and then back on again.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/acpi/power.c | 10 ++++++++++
 drivers/acpi/sleep.c |  1 +
 drivers/acpi/sleep.h |  1 +
 3 files changed, 12 insertions(+)

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index fcd4ce6..1d330a5 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -863,6 +863,16 @@ void acpi_resume_power_resources(void)
 
 		mutex_unlock(&resource->resource_lock);
 	}
+
+	mutex_unlock(&power_resource_list_lock);
+}
+
+void acpi_turn_off_unused_power_resources(void)
+{
+	struct acpi_power_resource *resource;
+
+	mutex_lock(&power_resource_list_lock);
+
 	list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
 		int result, state;
 
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index a4327af..097d630 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -474,6 +474,7 @@ static void acpi_pm_start(u32 acpi_state)
  */
 static void acpi_pm_end(void)
 {
+	acpi_turn_off_unused_power_resources();
 	acpi_scan_lock_release();
 	/*
 	 * This is necessary in case acpi_pm_finish() is not called during a
diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
index a9cc34e..a82ff74 100644
--- a/drivers/acpi/sleep.h
+++ b/drivers/acpi/sleep.h
@@ -6,6 +6,7 @@ extern struct list_head acpi_wakeup_device_list;
 extern struct mutex acpi_device_lock;
 
 extern void acpi_resume_power_resources(void);
+extern void acpi_turn_off_unused_power_resources(void);
 
 static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
 {
-- 
2.9.3