PCI / ACPI / PM: Platform support for PCI PME wake-up
Although the majority of PCI devices can generate PMEs that in
principle may be used to wake up devices suspended at run time,
platform support is generally necessary to convert PMEs into wake-up
events that can be delivered to the kernel. If ACPI is used for this
purpose, PME signals generated by a PCI device will trigger the ACPI
GPE associated with the device to generate an ACPI wake-up event that
we can set up a handler for, provided that everything is configured
correctly.
Unfortunately, the subset of PCI devices that have GPEs associated
with them is quite limited. The devices without dedicated GPEs have
to rely on the GPEs associated with other devices (in the majority of
cases their upstream bridges and, possibly, the root bridge) to
generate ACPI wake-up events in response to PME signals from them.
Add ACPI platform support for PCI PME wake-up:
o Add a framework making is possible to use ACPI system notify
handlers for run-time PM.
o Add new PCI platform callback ->run_wake() to struct
pci_platform_pm_ops allowing us to enable/disable the platform to
generate wake-up events for given device. Implemet this callback
for the ACPI platform.
o Define ACPI wake-up handlers for PCI devices and PCI root buses and
make the PCI-ACPI binding code register wake-up notifiers for all
PCI devices present in the ACPI tables.
o Add function pci_dev_run_wake() which can be used by PCI drivers to
check if given device is capable of generating wake-up events at
run time.
Developed in cooperation with Matthew Garrett <mjg@redhat.com>.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 64f55b6..9cd8bed 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -30,6 +30,7 @@
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/pm.h>
+#include <linux/pm_runtime.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
#include <linux/acpi.h>
@@ -528,6 +529,10 @@
if (flags != base_flags)
acpi_pci_osc_support(root, flags);
+ pci_acpi_add_bus_pm_notifier(device, root->bus);
+ if (device->wakeup.flags.run_wake)
+ device_set_run_wake(root->bus->bridge, true);
+
return 0;
end:
@@ -549,6 +554,9 @@
{
struct acpi_pci_root *root = acpi_driver_data(device);
+ device_set_run_wake(root->bus->bridge, false);
+ pci_acpi_remove_bus_pm_notifier(device);
+
kfree(root);
return 0;
}