Messages in this thread | | | Date | Wed, 25 Feb 2015 15:30:49 +0100 | From | Daniel Lezcano <> | Subject | Re: [PATCH 2/2] drivers: cpuidle: add driver/device checks in cpuidle_enter_freeze() |
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On 02/24/2015 06:58 PM, Lorenzo Pieralisi wrote: > 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 <rjw@rjwysocki.net> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@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); > +}
This is getting a bit fuzzy IMO. What means disabled ? :)
> /** > * 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;
I think this is exploding before because of dev == NULL in the line above.
> + 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); > } >
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