Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH v1 1/2] PM: runtime: Do not call __rpm_callback() from rpm_idle() | Date | Fri, 02 Dec 2022 15:30:28 +0100 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 accross __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") Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- drivers/base/power/runtime.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/base/power/runtime.c =================================================================== --- linux-pm.orig/drivers/base/power/runtime.c +++ linux-pm/drivers/base/power/runtime.c @@ -484,7 +484,17 @@ static int rpm_idle(struct device *dev, 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);
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