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authorJisheng Zhang <jszhang@marvell.com>2016-07-14 12:39:18 +0200
committerRussell King <rmk+kernel@armlinux.org.uk>2016-07-14 17:30:45 +0200
commitc3fbbf9308cc939663fdfb90334fe344947dd645 (patch)
treed386f180c0ae873c4ac5af81ab3e78c15ce9dd7c
parentARM: 8585/1: cpuidle: fix !cpuidle_ops[cpu].init case during init (diff)
downloadlinux-c3fbbf9308cc939663fdfb90334fe344947dd645.tar.xz
linux-c3fbbf9308cc939663fdfb90334fe344947dd645.zip
ARM: 8586/1: cpuidle: make arm_cpuidle_suspend() a bit more efficient
Currently, we check cpuidle_ops.suspend every time when entering a low-power idle state. But this check could be avoided in this hot path by moving it into arm_cpuidle_read_ops() to reduce arm_cpuidle_suspend overhead a bit. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/kernel/cpuidle.c17
1 files changed, 6 insertions, 11 deletions
diff --git a/arch/arm/kernel/cpuidle.c b/arch/arm/kernel/cpuidle.c
index 2129b297ec20..7dccc964d75f 100644
--- a/arch/arm/kernel/cpuidle.c
+++ b/arch/arm/kernel/cpuidle.c
@@ -47,18 +47,13 @@ int arm_cpuidle_simple_enter(struct cpuidle_device *dev,
* This function calls the underlying arch specific low level PM code as
* registered at the init time.
*
- * Returns -EOPNOTSUPP if no suspend callback is defined, the result of the
- * callback otherwise.
+ * Returns the result of the suspend callback.
*/
int arm_cpuidle_suspend(int index)
{
- int ret = -EOPNOTSUPP;
int cpu = smp_processor_id();
- if (cpuidle_ops[cpu].suspend)
- ret = cpuidle_ops[cpu].suspend(index);
-
- return ret;
+ return cpuidle_ops[cpu].suspend(index);
}
/**
@@ -92,8 +87,8 @@ static const struct cpuidle_ops *__init arm_cpuidle_get_ops(const char *method)
* process.
*
* Return 0 on sucess, -ENOENT if no 'enable-method' is defined, -EOPNOTSUPP if
- * no cpuidle_ops is registered for the 'enable-method', or if no init callback
- * is defined.
+ * no cpuidle_ops is registered for the 'enable-method', or if either init or
+ * suspend callback isn't defined.
*/
static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
{
@@ -111,8 +106,8 @@ static int __init arm_cpuidle_read_ops(struct device_node *dn, int cpu)
return -EOPNOTSUPP;
}
- if (!ops->init) {
- pr_warn("cpuidle_ops '%s': no init callback\n",
+ if (!ops->init || !ops->suspend) {
+ pr_warn("cpuidle_ops '%s': no init or suspend callback\n",
enable_method);
return -EOPNOTSUPP;
}