[PATCH V3 7/8] ARM: cpuidle: Register per cpuidle device

From: Daniel Lezcano
Date: Fri Mar 20 2015 - 07:44:38 EST


Some architectures have some cpus which does not support idle states.

Let the underlying low level code to return -ENXIO when it is not
possible to set an idle state.

Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
drivers/cpuidle/cpuidle-arm.c | 42 ++++++++++++++++++++++++++++++++++++++++--
1 file changed, 40 insertions(+), 2 deletions(-)

diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 1c94b88..e4a6eba 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/slab.h>

#include <asm/cpuidle.h>

@@ -94,6 +95,7 @@ static int __init arm_idle_init(void)
{
int cpu, ret;
struct cpuidle_driver *drv = &arm_idle_driver;
+ struct cpuidle_device *dev;

/*
* Initialize idle states data, starting at index 1.
@@ -105,18 +107,54 @@ static int __init arm_idle_init(void)
if (ret <= 0)
return ret ? : -ENODEV;

+ ret = cpuidle_register_driver(drv);
+ if (ret) {
+ pr_err("Failed to register cpuidle driver\n");
+ return ret;
+ }
+
/*
* Call arch CPU operations in order to initialize
* idle states suspend back-end specific data
*/
for_each_possible_cpu(cpu) {
ret = arm_cpuidle_init(cpu);
+
+ /* This cpu does not support any idle states */
+ if (ret == -ENXIO)
+ continue;
+
if (ret) {
pr_err("CPU %d failed to init idle CPU ops\n", cpu);
- return ret;
+ goto out_fail;
+ }
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ pr_err("Failed to allocate cpuidle device\n");
+ goto out_fail;
+ }
+ dev->cpu = cpu;
+
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("Failed to register cpuidle device for CPU %d\n",
+ cpu);
+ kfree(dev);
+ goto out_fail;
}
}

- return cpuidle_register(drv, NULL);
+ return 0;
+out_fail:
+ while (--cpu >= 0) {
+ dev = per_cpu(cpuidle_devices, cpu);
+ cpuidle_unregister_device(dev);
+ kfree(dev);
+ }
+
+ cpuidle_unregister_driver(drv);
+
+ return ret;
}
device_initcall(arm_idle_init);
--
1.9.1

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