From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Some architectures have some cpus which does not support idle states.
Let the underlying low level code to return -ENOSYS when it is not
possible to set an idle state.
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
[Minor clean ups and fixes of the per-cpu variable]
---
drivers/cpuidle/cpuidle-arm.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
index 1c94b88..f7cdb73 100644
--- a/drivers/cpuidle/cpuidle-arm.c
+++ b/drivers/cpuidle/cpuidle-arm.c
@@ -17,11 +17,14 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/slab.h>
#include <asm/cpuidle.h>
#include "dt_idle_states.h"
+static DEFINE_PER_CPU(struct cpuidle_device, *cpuidle_arm_dev);
+
/*
* arm_enter_idle_state - Programs CPU to enter the specified state
*
@@ -93,6 +96,7 @@ static const struct of_device_id arm_idle_state_match[] __initconst = {
static int __init arm_idle_init(void)
{
int cpu, ret;
+ struct cpuidle_device *dev;
struct cpuidle_driver *drv = &arm_idle_driver;
/*
@@ -105,18 +109,46 @@ 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 == -ENOSYS)
+ continue;
+
if (ret) {
pr_err("CPU %d failed to init idle CPU ops\n", cpu);
return ret;
}
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->cpu = cpu;
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("Failed to register cpuidle device for CPU %d\n",
+ cpu);
+ return ret;
+ }
+
+ per_cpu(cpuidle_arm_dev, cpu) = dev;
}
- return cpuidle_register(drv, NULL);
+ return 0;
}
device_initcall(arm_idle_init);
--
2.1.0
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