From 311aab73d273eb22be976055f6cab224f7279d5e Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Mon, 8 Aug 2011 23:39:36 +0200 Subject: PM / Runtime: Add might_sleep() to runtime PM functions Some of the entry points to pm runtime are not safe to call in atomic context unless pm_runtime_irq_safe() has been called. Inspecting the code, it is not immediately obvious that the functions sleep at all, as they run inside a spin_lock_irqsave, but under some conditions they can drop the lock and turn on irqs. If a driver incorrectly calls the pm_runtime apis, it can cause sleeping and irq processing when it expects to stay in atomic context. Add might_sleep_if to the majority of the __pm_runtime_* entry points to enforce correct usage. Add pm_runtime_put_sync_autosuspend to the list of functions that can be called in atomic context. Signed-off-by: Colin Cross Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki --- Documentation/power/runtime_pm.txt | 1 + drivers/base/power/runtime.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 4ce5450ab6e8..62f37bc3866f 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -484,6 +484,7 @@ pm_runtime_resume() pm_runtime_get_sync() pm_runtime_put_sync() pm_runtime_put_sync_suspend() +pm_runtime_put_sync_autosuspend() 5. Runtime PM Initialization, Device Probing and Removal diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index acb3f83b8079..04e18abb50bb 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -732,13 +732,16 @@ EXPORT_SYMBOL_GPL(pm_schedule_suspend); * return immediately if it is larger than zero. Then carry out an idle * notification, either synchronous or asynchronous. * - * This routine may be called in atomic context if the RPM_ASYNC flag is set. + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ int __pm_runtime_idle(struct device *dev, int rpmflags) { unsigned long flags; int retval; + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); + if (rpmflags & RPM_GET_PUT) { if (!atomic_dec_and_test(&dev->power.usage_count)) return 0; @@ -761,13 +764,16 @@ EXPORT_SYMBOL_GPL(__pm_runtime_idle); * return immediately if it is larger than zero. Then carry out a suspend, * either synchronous or asynchronous. * - * This routine may be called in atomic context if the RPM_ASYNC flag is set. + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ int __pm_runtime_suspend(struct device *dev, int rpmflags) { unsigned long flags; int retval; + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); + if (rpmflags & RPM_GET_PUT) { if (!atomic_dec_and_test(&dev->power.usage_count)) return 0; @@ -789,13 +795,16 @@ EXPORT_SYMBOL_GPL(__pm_runtime_suspend); * If the RPM_GET_PUT flag is set, increment the device's usage count. Then * carry out a resume, either synchronous or asynchronous. * - * This routine may be called in atomic context if the RPM_ASYNC flag is set. + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ int __pm_runtime_resume(struct device *dev, int rpmflags) { unsigned long flags; int retval; + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); + if (rpmflags & RPM_GET_PUT) atomic_inc(&dev->power.usage_count); -- cgit v1.2.3-58-ga151