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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-01-17 17:11:05 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-01-17 17:11:05 +0400
commitbc9b6407bd6df3ab7189e5622816bbc11ae9d2d8 (patch)
tree8f44ae6c9750b271eb423787e19db1288b53c42e /drivers/acpi/device_pm.c
parent6a8dd80821c215bc49bf6b108e85c1738c82bf43 (diff)
downloadlinux-bc9b6407bd6df3ab7189e5622816bbc11ae9d2d8.tar.xz
ACPI / PM: Rework the handling of devices depending on power resources
Commit 0090def6 (ACPI: Add interface to register/unregister device to/from power resources) made it possible to indicate to the ACPI core that if the given device depends on any power resources, then it should be resumed as soon as all of the power resources required by it to transition to the D0 power state have been turned on. Unfortunately, however, this was a mistake, because all devices depending on power resources should be treated this way (i.e. they should be resumed when all power resources required by their D0 state have been turned on) and for the majority of those devices the ACPI core can figure out by itself which (physical) devices depend on what power resources. For this reason, replace the code added by commit 0090def6 with a new, much more straightforward, mechanism that will be used internally by the ACPI core and remove all references to that code from kernel subsystems using ACPI. For the cases when there are (physical) devices that should be resumed whenever a not directly related ACPI device node goes into D0 as a result of power resources configuration changes, like in the SATA case, add two new routines, acpi_dev_pm_add_dependent() and acpi_dev_pm_remove_dependent(), allowing subsystems to manage such dependencies. Convert the SATA subsystem to use the new functions accordingly. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/device_pm.c')
-rw-r--r--drivers/acpi/device_pm.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 995019063f64..8be4b29e38aa 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -665,3 +665,59 @@ void acpi_dev_pm_detach(struct device *dev, bool power_off)
}
}
EXPORT_SYMBOL_GPL(acpi_dev_pm_detach);
+
+/**
+ * acpi_dev_pm_add_dependent - Add physical device depending for PM.
+ * @handle: Handle of ACPI device node.
+ * @depdev: Device depending on that node for PM.
+ */
+void acpi_dev_pm_add_dependent(acpi_handle handle, struct device *depdev)
+{
+ struct acpi_device_physical_node *dep;
+ struct acpi_device *adev;
+
+ if (!depdev || acpi_bus_get_device(handle, &adev))
+ return;
+
+ mutex_lock(&adev->physical_node_lock);
+
+ list_for_each_entry(dep, &adev->power_dependent, node)
+ if (dep->dev == depdev)
+ goto out;
+
+ dep = kzalloc(sizeof(*dep), GFP_KERNEL);
+ if (dep) {
+ dep->dev = depdev;
+ list_add_tail(&dep->node, &adev->power_dependent);
+ }
+
+ out:
+ mutex_unlock(&adev->physical_node_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_pm_add_dependent);
+
+/**
+ * acpi_dev_pm_remove_dependent - Remove physical device depending for PM.
+ * @handle: Handle of ACPI device node.
+ * @depdev: Device depending on that node for PM.
+ */
+void acpi_dev_pm_remove_dependent(acpi_handle handle, struct device *depdev)
+{
+ struct acpi_device_physical_node *dep;
+ struct acpi_device *adev;
+
+ if (!depdev || acpi_bus_get_device(handle, &adev))
+ return;
+
+ mutex_lock(&adev->physical_node_lock);
+
+ list_for_each_entry(dep, &adev->power_dependent, node)
+ if (dep->dev == depdev) {
+ list_del(&dep->node);
+ kfree(dep);
+ break;
+ }
+
+ mutex_unlock(&adev->physical_node_lock);
+}
+EXPORT_SYMBOL_GPL(acpi_dev_pm_remove_dependent);