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authorKevin Hilman <khilman@ti.com>2011-08-05 21:45:20 +0200
committerRafael J. Wysocki <rjw@sisk.pl>2011-08-05 21:45:20 +0200
commit02b26774afebb2d62695ba3230319d70d8c6cc2d (patch)
tree956c4056fcb42d2c2b2a75e20d3ad98f148865fc /drivers
parentfe202fde50a986a8510c62a76dc8733c1a8fac86 (diff)
PM / Runtime: Allow _put_sync() from interrupts-disabled context
Currently the use of pm_runtime_put_sync() is not safe from interrupts-disabled context because rpm_idle() will release the spinlock and enable interrupts for the idle callbacks. This enables interrupts during a time where interrupts were expected to be disabled, and can have strange side effects on drivers that expected interrupts to be disabled. This is not a bug since the documentation clearly states that only _put_sync_suspend() is safe in IRQ-safe mode. However, pm_runtime_put_sync() could be made safe when in IRQ-safe mode by releasing the spinlock but not re-enabling interrupts, which is what this patch aims to do. Problem was found when using some buggy drivers that set pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled context. Reported-by: Colin Cross <ccross@google.com> Tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/base/power/runtime.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 8dc247c974a..acb3f83b807 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -226,11 +226,17 @@ static int rpm_idle(struct device *dev, int rpmflags)
callback = NULL;
if (callback) {
- spin_unlock_irq(&dev->power.lock);
+ if (dev->power.irq_safe)
+ spin_unlock(&dev->power.lock);
+ else
+ spin_unlock_irq(&dev->power.lock);
callback(dev);
- spin_lock_irq(&dev->power.lock);
+ if (dev->power.irq_safe)
+ spin_lock(&dev->power.lock);
+ else
+ spin_lock_irq(&dev->power.lock);
}
dev->power.idle_notification = false;