1 files changed, 397 insertions, 167 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 665e93ca0b40..361a7721a6a8 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * drivers/acpi/power.c - ACPI Power Resources management.
  *
@@ -5,20 +6,6 @@
  * Author: Andy Grover <andrew.grover@intel.com>
  * Author: Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or (at
- *  your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful, but
- *  WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- *  General Public License for more details.
- *
- * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 
 /*
@@ -26,7 +13,7 @@
  * 1. via "Device Specific (D-State) Control"
  * 2. via "Power Resource Control".
  * The code below deals with ACPI Power Resources control.
- * 
+ *
  * An ACPI "power resource object" represents a software controllable power
  * plane, clock plane, or other resource depended on by a device.
  *
@@ -34,36 +21,42 @@
  * may be shared by multiple devices.
  */
 
+#define pr_fmt(fmt) "ACPI: PM: " fmt
+
+#include <linux/delay.h>
+#include <linux/dmi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/slab.h>
+#include <linux/string_choices.h>
 #include <linux/pm_runtime.h>
 #include <linux/sysfs.h>
 #include <linux/acpi.h>
 #include "sleep.h"
 #include "internal.h"
 
-#define _COMPONENT			ACPI_POWER_COMPONENT
-ACPI_MODULE_NAME("power");
 #define ACPI_POWER_CLASS		"power_resource"
 #define ACPI_POWER_DEVICE_NAME		"Power Resource"
-#define ACPI_POWER_FILE_INFO		"info"
-#define ACPI_POWER_FILE_STATUS		"state"
 #define ACPI_POWER_RESOURCE_STATE_OFF	0x00
 #define ACPI_POWER_RESOURCE_STATE_ON	0x01
 #define ACPI_POWER_RESOURCE_STATE_UNKNOWN 0xFF
 
+struct acpi_power_dependent_device {
+	struct device *dev;
+	struct list_head node;
+};
+
 struct acpi_power_resource {
 	struct acpi_device device;
 	struct list_head list_node;
-	char *name;
 	u32 system_level;
 	u32 order;
 	unsigned int ref_count;
-	bool wakeup_enabled;
+	u8 state;
 	struct mutex resource_lock;
+	struct list_head dependents;
 };
 
 struct acpi_power_resource_entry {
@@ -71,6 +64,9 @@ struct acpi_power_resource_entry {
 	struct acpi_power_resource *resource;
 };
 
+static bool hp_eb_gp12pxp_quirk;
+static bool unused_power_resources_quirk;
+
 static LIST_HEAD(acpi_power_resource_list);
 static DEFINE_MUTEX(power_resource_list_lock);
 
@@ -78,6 +74,11 @@ static DEFINE_MUTEX(power_resource_list_lock);
                              Power Resource Management
    -------------------------------------------------------------------------- */
 
+static inline const char *resource_dev_name(struct acpi_power_resource *pr)
+{
+	return dev_name(&pr->device.dev);
+}
+
 static inline
 struct acpi_power_resource *to_power_resource(struct acpi_device *device)
 {
@@ -86,9 +87,9 @@ struct acpi_power_resource *to_power_resource(struct acpi_device *device)
 
 static struct acpi_power_resource *acpi_power_get_context(acpi_handle handle)
 {
-	struct acpi_device *device;
+	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 
-	if (acpi_bus_get_device(handle, &device))
+	if (!device)
 		return NULL;
 
 	return to_power_resource(device);
@@ -156,6 +157,7 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 
 	for (i = start; i < package->package.count; i++) {
 		union acpi_object *element = &package->package.elements[i];
+		struct acpi_device *rdev;
 		acpi_handle rhandle;
 
 		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
@@ -172,10 +174,11 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 		if (acpi_power_resource_is_dup(package, start, i))
 			continue;
 
-		err = acpi_add_power_resource(rhandle);
-		if (err)
+		rdev = acpi_add_power_resource(rhandle);
+		if (!rdev) {
+			err = -ENODEV;
 			break;
-
+		}
 		err = acpi_power_resources_list_add(rhandle, list);
 		if (err)
 			break;
@@ -186,50 +189,54 @@ int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
 	return err;
 }
 
-static int acpi_power_get_state(acpi_handle handle, int *state)
+static int __get_state(acpi_handle handle, u8 *state)
 {
 	acpi_status status = AE_OK;
 	unsigned long long sta = 0;
-	char node_name[5];
-	struct acpi_buffer buffer = { sizeof(node_name), node_name };
-
-
-	if (!handle || !state)
-		return -EINVAL;
+	u8 cur_state;
 
 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 	if (ACPI_FAILURE(status))
 		return -ENODEV;
 
-	*state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
-			      ACPI_POWER_RESOURCE_STATE_OFF;
+	cur_state = sta & ACPI_POWER_RESOURCE_STATE_ON;
+
+	acpi_handle_debug(handle, "Power resource is %s\n",
+			  str_on_off(cur_state));
 
-	acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+	*state = cur_state;
+	return 0;
+}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
-			  node_name,
-				*state ? "on" : "off"));
+static int acpi_power_get_state(struct acpi_power_resource *resource, u8 *state)
+{
+	if (resource->state == ACPI_POWER_RESOURCE_STATE_UNKNOWN) {
+		int ret;
 
+		ret = __get_state(resource->device.handle, &resource->state);
+		if (ret)
+			return ret;
+	}
+
+	*state = resource->state;
 	return 0;
 }
 
-static int acpi_power_get_list_state(struct list_head *list, int *state)
+static int acpi_power_get_list_state(struct list_head *list, u8 *state)
 {
 	struct acpi_power_resource_entry *entry;
-	int cur_state;
+	u8 cur_state = ACPI_POWER_RESOURCE_STATE_OFF;
 
 	if (!list || !state)
 		return -EINVAL;
 
 	/* The state of the list is 'on' IFF all resources are 'on'. */
-	cur_state = 0;
 	list_for_each_entry(entry, list, node) {
 		struct acpi_power_resource *resource = entry->resource;
-		acpi_handle handle = resource->device.handle;
 		int result;
 
 		mutex_lock(&resource->resource_lock);
-		result = acpi_power_get_state(handle, &cur_state);
+		result = acpi_power_get_state(resource, &cur_state);
 		mutex_unlock(&resource->resource_lock);
 		if (result)
 			return result;
@@ -238,23 +245,155 @@ static int acpi_power_get_list_state(struct list_head *list, int *state)
 			break;
 	}
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource list is %s\n",
-			  cur_state ? "on" : "off"));
+	pr_debug("Power resource list is %s\n", str_on_off(cur_state));
 
 	*state = cur_state;
 	return 0;
 }
 
+static int
+acpi_power_resource_add_dependent(struct acpi_power_resource *resource,
+				  struct device *dev)
+{
+	struct acpi_power_dependent_device *dep;
+	int ret = 0;
+
+	mutex_lock(&resource->resource_lock);
+	list_for_each_entry(dep, &resource->dependents, node) {
+		/* Only add it once */
+		if (dep->dev == dev)
+			goto unlock;
+	}
+
+	dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+	if (!dep) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	dep->dev = dev;
+	list_add_tail(&dep->node, &resource->dependents);
+	dev_dbg(dev, "added power dependency to [%s]\n",
+		resource_dev_name(resource));
+
+unlock:
+	mutex_unlock(&resource->resource_lock);
+	return ret;
+}
+
+static void
+acpi_power_resource_remove_dependent(struct acpi_power_resource *resource,
+				     struct device *dev)
+{
+	struct acpi_power_dependent_device *dep;
+
+	mutex_lock(&resource->resource_lock);
+	list_for_each_entry(dep, &resource->dependents, node) {
+		if (dep->dev == dev) {
+			list_del(&dep->node);
+			kfree(dep);
+			dev_dbg(dev, "removed power dependency to [%s]\n",
+				resource_dev_name(resource));
+			break;
+		}
+	}
+	mutex_unlock(&resource->resource_lock);
+}
+
+/**
+ * acpi_device_power_add_dependent - Add dependent device of this ACPI device
+ * @adev: ACPI device pointer
+ * @dev: Dependent device
+ *
+ * If @adev has non-empty _PR0 the @dev is added as dependent device to all
+ * power resources returned by it. This means that whenever these power
+ * resources are turned _ON the dependent devices get runtime resumed. This
+ * is needed for devices such as PCI to allow its driver to re-initialize
+ * it after it went to D0uninitialized.
+ *
+ * If @adev does not have _PR0 this does nothing.
+ *
+ * Returns %0 in case of success and negative errno otherwise.
+ */
+int acpi_device_power_add_dependent(struct acpi_device *adev,
+				    struct device *dev)
+{
+	struct acpi_power_resource_entry *entry;
+	struct list_head *resources;
+	int ret;
+
+	if (!adev->flags.power_manageable)
+		return 0;
+
+	resources = &adev->power.states[ACPI_STATE_D0].resources;
+	list_for_each_entry(entry, resources, node) {
+		ret = acpi_power_resource_add_dependent(entry->resource, dev);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	list_for_each_entry(entry, resources, node)
+		acpi_power_resource_remove_dependent(entry->resource, dev);
+
+	return ret;
+}
+
+/**
+ * acpi_device_power_remove_dependent - Remove dependent device
+ * @adev: ACPI device pointer
+ * @dev: Dependent device
+ *
+ * Does the opposite of acpi_device_power_add_dependent() and removes the
+ * dependent device if it is found. Can be called to @adev that does not
+ * have _PR0 as well.
+ */
+void acpi_device_power_remove_dependent(struct acpi_device *adev,
+					struct device *dev)
+{
+	struct acpi_power_resource_entry *entry;
+	struct list_head *resources;
+
+	if (!adev->flags.power_manageable)
+		return;
+
+	resources = &adev->power.states[ACPI_STATE_D0].resources;
+	list_for_each_entry_reverse(entry, resources, node)
+		acpi_power_resource_remove_dependent(entry->resource, dev);
+}
+
 static int __acpi_power_on(struct acpi_power_resource *resource)
 {
+	acpi_handle handle = resource->device.handle;
+	struct acpi_power_dependent_device *dep;
 	acpi_status status = AE_OK;
 
-	status = acpi_evaluate_object(resource->device.handle, "_ON", NULL, NULL);
-	if (ACPI_FAILURE(status))
+	status = acpi_evaluate_object(handle, "_ON", NULL, NULL);
+	if (ACPI_FAILURE(status)) {
+		resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 		return -ENODEV;
+	}
+
+	resource->state = ACPI_POWER_RESOURCE_STATE_ON;
+
+	acpi_handle_debug(handle, "Power resource turned on\n");
+
+	/*
+	 * If there are other dependents on this power resource we need to
+	 * resume them now so that their drivers can re-initialize the
+	 * hardware properly after it went back to D0.
+	 */
+	if (list_empty(&resource->dependents) ||
+	    list_is_singular(&resource->dependents))
+		return 0;
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned on\n",
-			  resource->name));
+	list_for_each_entry(dep, &resource->dependents, node) {
+		dev_dbg(dep->dev, "runtime resuming because [%s] turned on\n",
+			resource_dev_name(resource));
+		pm_request_resume(dep->dev);
+	}
 
 	return 0;
 }
@@ -264,9 +403,8 @@ static int acpi_power_on_unlocked(struct acpi_power_resource *resource)
 	int result = 0;
 
 	if (resource->ref_count++) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Power resource [%s] already on\n",
-				  resource->name));
+		acpi_handle_debug(resource->device.handle,
+				  "Power resource already on\n");
 	} else {
 		result = __acpi_power_on(resource);
 		if (result)
@@ -287,15 +425,19 @@ static int acpi_power_on(struct acpi_power_resource *resource)
 
 static int __acpi_power_off(struct acpi_power_resource *resource)
 {
+	acpi_handle handle = resource->device.handle;
 	acpi_status status;
 
-	status = acpi_evaluate_object(resource->device.handle, "_OFF",
-				      NULL, NULL);
-	if (ACPI_FAILURE(status))
+	status = acpi_evaluate_object(handle, "_OFF", NULL, NULL);
+	if (ACPI_FAILURE(status)) {
+		resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 		return -ENODEV;
+	}
+
+	resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
+
+	acpi_handle_debug(handle, "Power resource turned off\n");
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Power resource [%s] turned off\n",
-			  resource->name));
 	return 0;
 }
 
@@ -304,16 +446,14 @@ static int acpi_power_off_unlocked(struct acpi_power_resource *resource)
 	int result = 0;
 
 	if (!resource->ref_count) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Power resource [%s] already off\n",
-				  resource->name));
+		acpi_handle_debug(resource->device.handle,
+				  "Power resource already off\n");
 		return 0;
 	}
 
 	if (--resource->ref_count) {
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Power resource [%s] still in use\n",
-				  resource->name));
+		acpi_handle_debug(resource->device.handle,
+				  "Power resource still in use\n");
 	} else {
 		result = __acpi_power_off(resource);
 		if (result)
@@ -480,21 +620,19 @@ int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
 
 	list_for_each_entry(entry, list, node) {
 		struct acpi_power_resource *resource = entry->resource;
-		acpi_handle handle = resource->device.handle;
-		int result;
-		int state;
+		u8 state;
 
 		mutex_lock(&resource->resource_lock);
 
-		result = acpi_power_get_state(handle, &state);
-		if (result) {
-			mutex_unlock(&resource->resource_lock);
-			return result;
-		}
-		if (state == ACPI_POWER_RESOURCE_STATE_ON) {
-			resource->ref_count++;
-			resource->wakeup_enabled = true;
-		}
+		/*
+		 * Make sure that the power resource state and its reference
+		 * counter value are consistent with each other.
+		 */
+		if (!resource->ref_count &&
+		    !acpi_power_get_state(resource, &state) &&
+		    state == ACPI_POWER_RESOURCE_STATE_ON)
+			__acpi_power_off(resource);
+
 		if (system_level > resource->system_level)
 			system_level = resource->system_level;
 
@@ -526,7 +664,7 @@ int acpi_power_wakeup_list_init(struct list_head *list, int *system_level_p)
  * -ENODEV if the execution of either _DSW or _PSW has failed
  */
 int acpi_device_sleep_wake(struct acpi_device *dev,
-                           int enable, int sleep_state, int dev_state)
+			   int enable, int sleep_state, int dev_state)
 {
 	union acpi_object in_arg[3];
 	struct acpi_object_list arg_list = { 3, in_arg };
@@ -535,12 +673,12 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
 	/*
 	 * Try to execute _DSW first.
 	 *
-	 * Three agruments are needed for the _DSW object:
+	 * Three arguments are needed for the _DSW object:
 	 * Argument 0: enable/disable the wake capabilities
 	 * Argument 1: target system state
 	 * Argument 2: target device state
 	 * When _DSW object is called to disable the wake capabilities, maybe
-	 * the first argument is filled. The values of the other two agruments
+	 * the first argument is filled. The values of the other two arguments
 	 * are meaningless.
 	 */
 	in_arg[0].type = ACPI_TYPE_INTEGER;
@@ -553,7 +691,7 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
 	if (ACPI_SUCCESS(status)) {
 		return 0;
 	} else if (status != AE_NOT_FOUND) {
-		printk(KERN_ERR PREFIX "_DSW execution failed\n");
+		acpi_handle_info(dev->handle, "_DSW execution failed\n");
 		dev->wakeup.flags.valid = 0;
 		return -ENODEV;
 	}
@@ -561,7 +699,7 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
 	/* Execute _PSW */
 	status = acpi_execute_simple_method(dev->handle, "_PSW", enable);
 	if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
-		printk(KERN_ERR PREFIX "_PSW execution failed\n");
+		acpi_handle_info(dev->handle, "_PSW execution failed\n");
 		dev->wakeup.flags.valid = 0;
 		return -ENODEV;
 	}
@@ -571,13 +709,12 @@ int acpi_device_sleep_wake(struct acpi_device *dev,
 
 /*
  * Prepare a wakeup device, two steps (Ref ACPI 2.0:P229):
- * 1. Power on the power resources required for the wakeup device 
+ * 1. Power on the power resources required for the wakeup device
  * 2. Execute _DSW (Device Sleep Wake) or (deprecated in ACPI 3.0) _PSW (Power
  *    State Wake) for the device, if present
  */
 int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 {
-	struct acpi_power_resource_entry *entry;
 	int err = 0;
 
 	if (!dev || !dev->wakeup.flags.valid)
@@ -585,36 +722,31 @@ int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state)
 
 	mutex_lock(&acpi_device_lock);
 
+	dev_dbg(&dev->dev, "Enabling wakeup power (count %d)\n",
+		dev->wakeup.prepare_count);
+
 	if (dev->wakeup.prepare_count++)
 		goto out;
 
-	list_for_each_entry(entry, &dev->wakeup.resources, node) {
-		struct acpi_power_resource *resource = entry->resource;
-
-		mutex_lock(&resource->resource_lock);
-
-		if (!resource->wakeup_enabled) {
-			err = acpi_power_on_unlocked(resource);
-			if (!err)
-				resource->wakeup_enabled = true;
-		}
-
-		mutex_unlock(&resource->resource_lock);
-
-		if (err) {
-			dev_err(&dev->dev,
-				"Cannot turn wakeup power resources on\n");
-			dev->wakeup.flags.valid = 0;
-			goto out;
-		}
+	err = acpi_power_on_list(&dev->wakeup.resources);
+	if (err) {
+		dev_err(&dev->dev, "Cannot turn on wakeup power resources\n");
+		dev->wakeup.flags.valid = 0;
+		goto out;
 	}
+
 	/*
 	 * Passing 3 as the third argument below means the device may be
 	 * put into arbitrary power state afterward.
 	 */
 	err = acpi_device_sleep_wake(dev, 1, sleep_state, 3);
-	if (err)
+	if (err) {
+		acpi_power_off_list(&dev->wakeup.resources);
 		dev->wakeup.prepare_count = 0;
+		goto out;
+	}
+
+	dev_dbg(&dev->dev, "Wakeup power enabled\n");
 
  out:
 	mutex_unlock(&acpi_device_lock);
@@ -637,41 +769,39 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 
 	mutex_lock(&acpi_device_lock);
 
-	if (--dev->wakeup.prepare_count > 0)
+	dev_dbg(&dev->dev, "Disabling wakeup power (count %d)\n",
+		dev->wakeup.prepare_count);
+
+	/* Do nothing if wakeup power has not been enabled for this device. */
+	if (dev->wakeup.prepare_count <= 0)
 		goto out;
 
-	/*
-	 * Executing the code below even if prepare_count is already zero when
-	 * the function is called may be useful, for example for initialisation.
-	 */
-	if (dev->wakeup.prepare_count < 0)
-		dev->wakeup.prepare_count = 0;
+	if (--dev->wakeup.prepare_count > 0)
+		goto out;
 
 	err = acpi_device_sleep_wake(dev, 0, 0, 0);
 	if (err)
 		goto out;
 
+	/*
+	 * All of the power resources in the list need to be turned off even if
+	 * there are errors.
+	 */
 	list_for_each_entry(entry, &dev->wakeup.resources, node) {
-		struct acpi_power_resource *resource = entry->resource;
-
-		mutex_lock(&resource->resource_lock);
-
-		if (resource->wakeup_enabled) {
-			err = acpi_power_off_unlocked(resource);
-			if (!err)
-				resource->wakeup_enabled = false;
-		}
-
-		mutex_unlock(&resource->resource_lock);
+		int ret;
 
-		if (err) {
-			dev_err(&dev->dev,
-				"Cannot turn wakeup power resources off\n");
-			dev->wakeup.flags.valid = 0;
-			break;
-		}
+		ret = acpi_power_off(entry->resource);
+		if (ret && !err)
+			err = ret;
+	}
+	if (err) {
+		dev_err(&dev->dev, "Cannot turn off wakeup power resources\n");
+		dev->wakeup.flags.valid = 0;
+		goto out;
 	}
 
+	dev_dbg(&dev->dev, "Wakeup power disabled\n");
+
  out:
 	mutex_unlock(&acpi_device_lock);
 	return err;
@@ -679,8 +809,8 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
 
 int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
 {
+	u8 list_state = ACPI_POWER_RESOURCE_STATE_OFF;
 	int result = 0;
-	int list_state = 0;
 	int i = 0;
 
 	if (!device || !state)
@@ -767,15 +897,16 @@ static void acpi_release_power_resource(struct device *dev)
 	kfree(resource);
 }
 
-static ssize_t acpi_power_in_use_show(struct device *dev,
-				      struct device_attribute *attr,
-				      char *buf) {
+static ssize_t resource_in_use_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
 	struct acpi_power_resource *resource;
 
 	resource = to_power_resource(to_acpi_device(dev));
 	return sprintf(buf, "%u\n", !!resource->ref_count);
 }
-static DEVICE_ATTR(resource_in_use, 0444, acpi_power_in_use_show, NULL);
+static DEVICE_ATTR_RO(resource_in_use);
 
 static void acpi_power_sysfs_remove(struct acpi_device *device)
 {
@@ -801,50 +932,54 @@ static void acpi_power_add_resource_to_list(struct acpi_power_resource *resource
 	mutex_unlock(&power_resource_list_lock);
 }
 
-int acpi_add_power_resource(acpi_handle handle)
+struct acpi_device *acpi_add_power_resource(acpi_handle handle)
 {
+	struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 	struct acpi_power_resource *resource;
-	struct acpi_device *device = NULL;
 	union acpi_object acpi_object;
 	struct acpi_buffer buffer = { sizeof(acpi_object), &acpi_object };
 	acpi_status status;
-	int state, result = -ENODEV;
+	u8 state_dummy;
+	int result;
 
-	acpi_bus_get_device(handle, &device);
 	if (device)
-		return 0;
+		return device;
 
 	resource = kzalloc(sizeof(*resource), GFP_KERNEL);
 	if (!resource)
-		return -ENOMEM;
+		return NULL;
 
 	device = &resource->device;
 	acpi_init_device_object(device, handle, ACPI_BUS_TYPE_POWER,
-				ACPI_STA_DEFAULT);
+				acpi_release_power_resource);
 	mutex_init(&resource->resource_lock);
 	INIT_LIST_HEAD(&resource->list_node);
-	resource->name = device->pnp.bus_id;
-	strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
-	strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
+	INIT_LIST_HEAD(&resource->dependents);
+	strscpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
+	strscpy(acpi_device_class(device), ACPI_POWER_CLASS);
 	device->power.state = ACPI_STATE_UNKNOWN;
+	device->flags.match_driver = true;
 
-	/* Evalute the object to get the system level and resource order. */
+	/* Evaluate the object to get the system level and resource order. */
 	status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 	if (ACPI_FAILURE(status))
 		goto err;
 
 	resource->system_level = acpi_object.power_resource.system_level;
 	resource->order = acpi_object.power_resource.resource_order;
+	resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
 
-	result = acpi_power_get_state(handle, &state);
+	/* Get the initial state or just flip it on if that fails. */
+	if (acpi_power_get_state(resource, &state_dummy))
+		__acpi_power_on(resource);
+
+	acpi_handle_info(handle, "New power resource\n");
+
+	result = acpi_tie_acpi_dev(device);
 	if (result)
 		goto err;
 
-	printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
-	       acpi_device_bid(device), state ? "on" : "off");
-
-	device->flags.match_driver = true;
-	result = acpi_device_add(device, acpi_release_power_resource);
+	result = acpi_device_add(device);
 	if (result)
 		goto err;
 
@@ -853,14 +988,46 @@ int acpi_add_power_resource(acpi_handle handle)
 
 	acpi_power_add_resource_to_list(resource);
 	acpi_device_add_finalize(device);
-	return 0;
+	return device;
 
  err:
 	acpi_release_power_resource(&device->dev);
-	return result;
+	return NULL;
 }
 
 #ifdef CONFIG_ACPI_SLEEP
+static bool resource_is_gp12pxp(acpi_handle handle)
+{
+	const char *path;
+	bool ret;
+
+	path = acpi_handle_path(handle);
+	ret = path && strcmp(path, "\\_SB_.PCI0.GP12.PXP_") == 0;
+	kfree(path);
+
+	return ret;
+}
+
+static void acpi_resume_on_eb_gp12pxp(struct acpi_power_resource *resource)
+{
+	acpi_handle_notice(resource->device.handle,
+			   "HP EB quirk - turning OFF then ON\n");
+
+	__acpi_power_off(resource);
+	__acpi_power_on(resource);
+
+	/*
+	 * Use the same delay as DSDT uses in modem _RST method.
+	 *
+	 * Otherwise we get "Unable to change power state from unknown to D0,
+	 * device inaccessible" error for the modem PCI device after thaw.
+	 *
+	 * This power resource is normally being enabled only during thaw (once)
+	 * so this wait is not a performance issue.
+	 */
+	msleep(200);
+}
+
 void acpi_resume_power_resources(void)
 {
 	struct acpi_power_resource *resource;
@@ -868,11 +1035,13 @@ void acpi_resume_power_resources(void)
 	mutex_lock(&power_resource_list_lock);
 
 	list_for_each_entry(resource, &acpi_power_resource_list, list_node) {
-		int result, state;
+		int result;
+		u8 state;
 
 		mutex_lock(&resource->resource_lock);
 
-		result = acpi_power_get_state(resource->device.handle, &state);
+		resource->state = ACPI_POWER_RESOURCE_STATE_UNKNOWN;
+		result = acpi_power_get_state(resource, &state);
 		if (result) {
 			mutex_unlock(&resource->resource_lock);
 			continue;
@@ -880,8 +1049,14 @@ void acpi_resume_power_resources(void)
 
 		if (state == ACPI_POWER_RESOURCE_STATE_OFF
 		    && resource->ref_count) {
-			dev_info(&resource->device.dev, "Turning ON\n");
-			__acpi_power_on(resource);
+			if (hp_eb_gp12pxp_quirk &&
+			    resource_is_gp12pxp(resource->device.handle)) {
+				acpi_resume_on_eb_gp12pxp(resource);
+			} else {
+				acpi_handle_debug(resource->device.handle,
+						  "Turning ON\n");
+				__acpi_power_on(resource);
+			}
 		}
 
 		mutex_unlock(&resource->resource_lock);
@@ -889,27 +1064,76 @@ void acpi_resume_power_resources(void)
 
 	mutex_unlock(&power_resource_list_lock);
 }
+#endif
+
+static const struct dmi_system_id dmi_hp_elitebook_gp12pxp_quirk[] = {
+/*
+ * This laptop (and possibly similar models too) has power resource called
+ * "GP12.PXP_" for its WWAN modem.
+ *
+ * For this power resource to turn ON power for the modem it needs certain
+ * internal flag called "ONEN" to be set.
+ * This flag only gets set from this power resource "_OFF" method, while the
+ * actual modem power gets turned off during suspend by "GP12.PTS" method
+ * called from the global "_PTS" (Prepare To Sleep) method.
+ * On the other hand, this power resource "_OFF" method implementation just
+ * sets the aforementioned flag without actually doing anything else (it
+ * doesn't contain any code to actually turn off power).
+ *
+ * The above means that when upon hibernation finish we try to set this
+ * power resource back ON since its "_STA" method returns 0 (while the resource
+ * is still considered in use) its "_ON" method won't do anything since
+ * that "ONEN" flag is not set.
+ * Overall, this means the modem is dead until laptop is rebooted since its
+ * power has been cut by "_PTS" and its PCI configuration was lost and not able
+ * to be restored.
+ *
+ * The easiest way to workaround the issue is to call this power resource
+ * "_OFF" method before calling the "_ON" method to make sure the "ONEN"
+ * flag gets properly set.
+ */
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 855 G7 Notebook PC"),
+		},
+	},
+	{}
+};
+
+static const struct dmi_system_id dmi_leave_unused_power_resources_on[] = {
+	{
+		/*
+		 * The Toshiba Click Mini has a CPR3 power-resource which must
+		 * be on for the touchscreen to work, but which is not in any
+		 * _PR? lists. The other 2 affected power-resources are no-ops.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE Click Mini L9W-B"),
+		},
+	},
+	{}
+};
 
+/**
+ * acpi_turn_off_unused_power_resources - Turn off power resources not in use.
+ */
 void acpi_turn_off_unused_power_resources(void)
 {
 	struct acpi_power_resource *resource;
 
+	if (unused_power_resources_quirk)
+		return;
+
 	mutex_lock(&power_resource_list_lock);
 
 	list_for_each_entry_reverse(resource, &acpi_power_resource_list, list_node) {
-		int result, state;
-
 		mutex_lock(&resource->resource_lock);
 
-		result = acpi_power_get_state(resource->device.handle, &state);
-		if (result) {
-			mutex_unlock(&resource->resource_lock);
-			continue;
-		}
-
-		if (state == ACPI_POWER_RESOURCE_STATE_ON
-		    && !resource->ref_count) {
-			dev_info(&resource->device.dev, "Turning OFF\n");
+		if (!resource->ref_count &&
+		    resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
+			acpi_handle_debug(resource->device.handle, "Turning OFF\n");
 			__acpi_power_off(resource);
 		}
 
@@ -918,4 +1142,10 @@ void acpi_turn_off_unused_power_resources(void)
 
 	mutex_unlock(&power_resource_list_lock);
 }
-#endif
+
+void __init acpi_power_resources_init(void)
+{
+	hp_eb_gp12pxp_quirk = dmi_check_system(dmi_hp_elitebook_gp12pxp_quirk);
+	unused_power_resources_quirk =
+		dmi_check_system(dmi_leave_unused_power_resources_on);
+}