From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Rework the ACPI PM domain's PM callbacks to avoid resuming devices
during system suspend in order to modify their wakeup settings if
that isn't necessary.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/device_pm.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)
Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -812,6 +812,13 @@ int acpi_dev_runtime_resume(struct devic
struct acpi_device *adev = acpi_dev_pm_get_node(dev);
int error;
+ /*
+ * This only matters during system suspend, if acpi_subsys_prepare()
+ * has returned 1. In that case, we may be resumed through a child
+ * runtime resume, in which case our system suspend callbacks will need
+ * to be executed, so power.no_suspend has to be cleared.
+ */
+ dev->power.no_suspend = false;
if (!adev)
return 0;
@@ -912,12 +919,28 @@ EXPORT_SYMBOL_GPL(acpi_dev_resume_early)
*/
int acpi_subsys_prepare(struct device *dev)
{
+ struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+ u32 target_state;
+ int error, state;
+
+ if (!adev || !pm_runtime_enabled_and_suspended(dev))
+ return pm_generic_prepare(dev);
+
+ target_state = acpi_target_system_state();
+ error = acpi_dev_pm_get_state(dev, adev, target_state, NULL, &state);
+ if (error || state != adev->power.state
+ || device_may_wakeup(dev) != !!adev->wakeup.prepare_count) {
+ pm_runtime_resume(dev);
+ return pm_generic_prepare(dev);
+ }
/*
- * Follow PCI and resume devices suspended at run time before running
- * their system suspend callbacks.
+ * If this is a wakeup device, wakeup power has been enabled already for
+ * it during the preceding runtime suspend. Caveat: "sleep state" is
+ * one of the _DSW arguments, but that shouldn't matter for the devices
+ * using acpi_general_pm_domain.
*/
- pm_runtime_resume(dev);
- return pm_generic_prepare(dev);
+ error = pm_generic_prepare(dev);
+ return error ? error : 1;
}
EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
--
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