The changes in commit: 381063133246 ("PM / sleep: Re-implement suspend-to-idle handling")
let suspend-to-idle code bypass the cpuidle_select() function to enter the deepest idle state. The sanity checks carried out in cpuidle_select() are bypassed too and this can cause breakage on systems that try to suspend-to-idle with no registered cpuidle driver. This patch factors out a function cpuidle_device_disabled() that is used to carry out sanity checks (ie CPUidle is disabled on the cpu executing the code) in both cpuidle_select() and cpuidle_enter_freeze() so that the checks are unified and carried out in both control paths. Cc: Rafael J. Wysocki <r...@rjwysocki.net> Cc: Daniel Lezcano <daniel.lezc...@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com> --- drivers/cpuidle/cpuidle.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index f47edc6c..344fe6c 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -44,6 +44,12 @@ void disable_cpuidle(void) off = 1; } +static bool cpuidle_device_disabled(struct cpuidle_driver *drv, + struct cpuidle_device *dev) +{ + return (off || !initialized || !drv || !dev || !dev->enabled); +} + /** * cpuidle_play_dead - cpu off-lining * @@ -124,6 +130,11 @@ void cpuidle_enter_freeze(void) struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); int index; + if (cpuidle_device_disabled(drv, dev)) { + arch_cpu_idle(); + return; + } + /* * Find the deepest state with ->enter_freeze present, which guarantees * that interrupts won't be enabled when it exits and allows the tick to @@ -202,11 +213,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, */ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { - if (off || !initialized) - return -ENODEV; - - if (!drv || !dev || !dev->enabled) - return -EBUSY; + if (cpuidle_device_disabled(drv, dev)) + return -1; return cpuidle_curr_governor->select(drv, dev); } -- 2.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/