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-rw-r--r--drivers/acpi/bus.c29
-rw-r--r--drivers/acpi/device_pm.c8
-rw-r--r--drivers/acpi/internal.h2
-rw-r--r--drivers/acpi/power.c15
-rw-r--r--drivers/acpi/scan.c1
5 files changed, 48 insertions, 7 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 7a3ad929f095..a23903c8bea9 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -486,6 +486,35 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device)
Device Matching
-------------------------------------------------------------------------- */
+/**
+ * acpi_device_is_first_physical_node - Is given dev first physical node
+ * @adev: ACPI companion device
+ * @dev: Physical device to check
+ *
+ * Function checks if given @dev is the first physical devices attached to
+ * the ACPI companion device. This distinction is needed in some cases
+ * where the same companion device is shared between many physical devices.
+ *
+ * Note that the caller have to provide valid @adev pointer.
+ */
+bool acpi_device_is_first_physical_node(struct acpi_device *adev,
+ const struct device *dev)
+{
+ bool ret = false;
+
+ mutex_lock(&adev->physical_node_lock);
+ if (!list_empty(&adev->physical_node_list)) {
+ const struct acpi_device_physical_node *node;
+
+ node = list_first_entry(&adev->physical_node_list,
+ struct acpi_device_physical_node, node);
+ ret = node->dev == dev;
+ }
+ mutex_unlock(&adev->physical_node_lock);
+
+ return ret;
+}
+
/*
* acpi_companion_match() - Can we match via ACPI companion device
* @dev: Device in question
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 717afcdb5f4a..08dc3ec7e892 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -1123,6 +1123,14 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
if (dev->pm_domain)
return -EEXIST;
+ /*
+ * Only attach the power domain to the first device if the
+ * companion is shared by multiple. This is to prevent doing power
+ * management twice.
+ */
+ if (!acpi_device_is_first_physical_node(adev, dev))
+ return -EBUSY;
+
acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
dev->pm_domain = &acpi_general_pm_domain;
if (power_on) {
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index c529454532dc..df7f7aff327b 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -99,6 +99,8 @@ void acpi_device_add_finalize(struct acpi_device *device);
void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
bool acpi_device_is_present(struct acpi_device *adev);
bool acpi_device_is_battery(struct acpi_device *adev);
+bool acpi_device_is_first_physical_node(struct acpi_device *adev,
+ const struct device *dev);
/* --------------------------------------------------------------------------
Device Matching and Notification
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 93eac53b5110..ce68ae68840d 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -1,8 +1,10 @@
/*
- * acpi_power.c - ACPI Bus Power Management ($Revision: 39 $)
+ * drivers/acpi/power.c - ACPI Power Resources management.
*
- * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
- * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2001 - 2015 Intel Corp.
+ * Author: Andy Grover <andrew.grover@intel.com>
+ * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
@@ -27,10 +29,11 @@
* ACPI power-managed devices may be controlled in two ways:
* 1. via "Device Specific (D-State) Control"
* 2. via "Power Resource Control".
- * This module is used to manage devices relying on Power Resource Control.
+ * The code below deals with ACPI Power Resources control.
*
- * An ACPI "power resource object" describes a software controllable power
- * plane, clock plane, or other resource used by a power managed device.
+ * An ACPI "power resource object" represents a software controllable power
+ * plane, clock plane, or other resource depended on by a device.
+ *
* A device may rely on multiple power resources, and a power resource
* may be shared by multiple devices.
*/
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 2fe5a37c385c..01136b879038 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -115,7 +115,6 @@ int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
return 0;
}
-
bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
{
struct acpi_device_physical_node *pn;
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