diff options
| author | Kevin Hilman <khilman@ti.com> | 2011-08-05 21:45:20 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-08-05 21:45:20 +0200 |
| commit | 02b26774afebb2d62695ba3230319d70d8c6cc2d (patch) | |
| tree | 956c4056fcb42d2c2b2a75e20d3ad98f148865fc /drivers | |
| parent | fe202fde50a986a8510c62a76dc8733c1a8fac86 (diff) | |
| download | linux-02b26774afebb2d62695ba3230319d70d8c6cc2d.tar.bz2 | |
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.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 8dc247c974af..acb3f83b8079 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; |