alistair23-linux/drivers/acpi/wakeup.c
Rafael J. Wysocki cb1cb1780f ACPI / PM: Do not enable GPEs for system wakeup in advance
After commit 9630bdd9b1
(ACPI: Use GPE reference counting to support shared GPEs) the wakeup
enable mask bits of GPEs are set as soon as the GPEs are enabled to
wake up the system.  Unfortunately, this leads to a regression
reported by Michal Hocko, where a system is woken up from ACPI S5 by
a device that is not supposed to do that, because the wakeup enable
mask bit of this device's GPE is always set when
acpi_enter_sleep_state() calls acpi_hw_enable_all_wakeup_gpes(),
although it should only be set if the device is supposed to wake up
the system from the target state.

To work around this issue, rework the ACPI power management code so
that GPEs are not enabled to wake up the system upfront, but only
during a system state transition when the target state of the system
is known.  [Of course, this means that the reference counting of
"wakeup" GPEs doesn't really make sense and it is sufficient to
set/unset the wakeup mask bits for them during system sleep
transitions.  This will allow us to simplify the GPE handling code
quite a bit, but that change is too intrusive for 2.6.35.]

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15951

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-06-17 12:18:09 -04:00

117 lines
3.2 KiB
C

/*
* wakeup.c - support wakeup devices
* Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>
*/
#include <linux/init.h>
#include <linux/acpi.h>
#include <acpi/acpi_drivers.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include "internal.h"
#include "sleep.h"
/*
* We didn't lock acpi_device_lock in the file, because it invokes oops in
* suspend/resume and isn't really required as this is called in S-state. At
* that time, there is no device hotplug
**/
#define _COMPONENT ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("wakeup_devices")
/**
* acpi_enable_wakeup_device_prep - Prepare wake-up devices.
* @sleep_state: ACPI system sleep state.
*
* Enable all wake-up devices' power, unless the requested system sleep state is
* too deep.
*/
void acpi_enable_wakeup_device_prep(u8 sleep_state)
{
struct list_head *node, *next;
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev = container_of(node,
struct acpi_device,
wakeup_list);
if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
|| (sleep_state > (u32) dev->wakeup.sleep_state))
continue;
acpi_enable_wakeup_device_power(dev, sleep_state);
}
}
/**
* acpi_enable_wakeup_device - Enable wake-up device GPEs.
* @sleep_state: ACPI system sleep state.
*
* Enable all wake-up devices' GPEs, with the assumption that
* acpi_disable_all_gpes() was executed before, so we don't need to disable any
* GPEs here.
*/
void acpi_enable_wakeup_device(u8 sleep_state)
{
struct list_head *node, *next;
/*
* Caution: this routine must be invoked when interrupt is disabled
* Refer ACPI2.0: P212
*/
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev =
container_of(node, struct acpi_device, wakeup_list);
if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
|| sleep_state > (u32) dev->wakeup.sleep_state)
continue;
/* The wake-up power should have been enabled already. */
acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
ACPI_GPE_TYPE_WAKE);
}
}
/**
* acpi_disable_wakeup_device - Disable devices' wakeup capability.
* @sleep_state: ACPI system sleep state.
*
* This function only affects devices with wakeup.state.enabled set, which means
* that it reverses the changes made by acpi_enable_wakeup_device_prep().
*/
void acpi_disable_wakeup_device(u8 sleep_state)
{
struct list_head *node, *next;
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev =
container_of(node, struct acpi_device, wakeup_list);
if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
|| (sleep_state > (u32) dev->wakeup.sleep_state))
continue;
acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
ACPI_GPE_TYPE_WAKE);
acpi_disable_wakeup_device_power(dev);
}
}
int __init acpi_wakeup_device_init(void)
{
struct list_head *node, *next;
mutex_lock(&acpi_device_lock);
list_for_each_safe(node, next, &acpi_wakeup_device_list) {
struct acpi_device *dev = container_of(node,
struct acpi_device,
wakeup_list);
if (dev->wakeup.flags.always_enabled)
dev->wakeup.state.enabled = 1;
}
mutex_unlock(&acpi_device_lock);
return 0;
}