From: Rafael J. Wysocki rafael.j.wysocki@intel.com
[ Upstream commit bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 ]
Calling __rpm_callback() from rpm_idle() after adding device links support to the former is a clear mistake.
Not only it causes rpm_idle() to carry out unnecessary actions, but it is also against the assumption regarding the stability of PM-runtime status across __rpm_callback() invocations, because rpm_suspend() and rpm_resume() may run in parallel with __rpm_callback() when it is called by rpm_idle() and the device's PM-runtime status can be updated by any of them.
Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicin... Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Adrian Hunter adrian.hunter@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/base/power/runtime.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 997be3ac20a7..d36fb07190bf 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -484,7 +484,17 @@ static int rpm_idle(struct device *dev, int rpmflags)
dev->power.idle_notification = true;
- retval = __rpm_callback(callback, dev); + if (dev->power.irq_safe) + spin_unlock(&dev->power.lock); + else + spin_unlock_irq(&dev->power.lock); + + retval = callback(dev); + + if (dev->power.irq_safe) + spin_lock(&dev->power.lock); + else + spin_lock_irq(&dev->power.lock);
dev->power.idle_notification = false; wake_up_all(&dev->power.wait_queue);