Merge branch 'acpi-pm'

* acpi-pm:
  ACPI / bus: Move duplicate code to a separate new function
  mfd: Add support for Intel Sunrisepoint LPSS devices
  dmaengine: add a driver for Intel integrated DMA 64-bit
  mfd: make mfd_remove_devices() iterate in reverse order
  driver core: implement device_for_each_child_reverse()
  klist: implement klist_prev()
  Driver core: wakeup the parent device before trying probe
  ACPI / PM: Attach ACPI power domain only once
  PM / QoS: Make it possible to expose device latency tolerance to userspace
  ACPI / PM: Update the copyright notice and description of power.c

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index da0867899d10..4806b7f856c4 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -1119,6 +1119,14 @@ 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) {