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 <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);
+}
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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