path: root/drivers/base
diff options
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-01-05 02:18:42 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-01-09 13:09:16 +0100
commit7bf4e594c28afc67bc120a380ca774e43ca496d8 (patch)
tree8f8620cca96c6a29eb8c3a1f7c31e350f8e96ae8 /drivers/base
parent32bfa56ac158c1ebcc82df2518860f824be5e5be (diff)
PM / wakeup: Do not fail dev_pm_attach_wake_irq() unnecessarily
Returning an error code from dev_pm_attach_wake_irq() if device_wakeup_attach_irq() called by it returns an error is pointless, because the wakeup source used by it may be deleted by user space via sysfs at any time and in particular right after dev_pm_attach_wake_irq() has returned. Moreover, it requires the callers of dev_pm_attach_wake_irq() to create that wakeup source via device_wakeup_enable() upfront, but that obviously is racy with respect to the sysfs-based manipulations of it. To avoid the race, modify device_wakeup_attach_irq() to check that the wakeup source it is going to use is there (and return early otherwise), make it void (as it cannot fail after that change) and make dev_pm_attach_wake_irq() simply call it for the device unconditionally. Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base')
3 files changed, 10 insertions, 20 deletions
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index 7beee75399d4..21244c53e377 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -41,20 +41,15 @@ extern void dev_pm_disable_wake_irq_check(struct device *dev);
-extern int device_wakeup_attach_irq(struct device *dev,
- struct wake_irq *wakeirq);
+extern void device_wakeup_attach_irq(struct device *dev, struct wake_irq *wakeirq);
extern void device_wakeup_detach_irq(struct device *dev);
extern void device_wakeup_arm_wake_irqs(void);
extern void device_wakeup_disarm_wake_irqs(void);
-static inline int
-device_wakeup_attach_irq(struct device *dev,
- struct wake_irq *wakeirq)
- return 0;
+static inline void device_wakeup_attach_irq(struct device *dev,
+ struct wake_irq *wakeirq) {}
static inline void device_wakeup_detach_irq(struct device *dev)
diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index ae0429827f31..a8ac86e4d79e 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -33,7 +33,6 @@ static int dev_pm_attach_wake_irq(struct device *dev, int irq,
struct wake_irq *wirq)
unsigned long flags;
- int err;
if (!dev || !wirq)
return -EINVAL;
@@ -45,12 +44,11 @@ static int dev_pm_attach_wake_irq(struct device *dev, int irq,
return -EEXIST;
- err = device_wakeup_attach_irq(dev, wirq);
- if (!err)
- dev->power.wakeirq = wirq;
+ dev->power.wakeirq = wirq;
+ device_wakeup_attach_irq(dev, wirq);
spin_unlock_irqrestore(&dev->power.lock, flags);
- return err;
+ return 0;
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index b7b8b2fe89c6..e73a081c6397 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -291,22 +291,19 @@ EXPORT_SYMBOL_GPL(device_wakeup_enable);
* Call under the device's power.lock lock.
-int device_wakeup_attach_irq(struct device *dev,
+void device_wakeup_attach_irq(struct device *dev,
struct wake_irq *wakeirq)
struct wakeup_source *ws;
ws = dev->power.wakeup;
- if (!ws) {
- dev_err(dev, "forgot to call device_init_wakeup?\n");
- return -EINVAL;
- }
+ if (!ws)
+ return;
if (ws->wakeirq)
- return -EEXIST;
+ dev_err(dev, "Leftover wakeup IRQ found, overriding\n");
ws->wakeirq = wakeirq;
- return 0;

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