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author | Jisheng Zhang <jszhang@marvell.com> | 2016-07-14 11:39:18 +0100 |
---|---|---|
committer | Russell King <rmk+kernel@armlinux.org.uk> | 2016-07-14 16:30:45 +0100 |
commit | c3fbbf9308cc939663fdfb90334fe344947dd645 (patch) | |
tree | d386f180c0ae873c4ac5af81ab3e78c15ce9dd7c /arch/arm/kernel | |
parent | f222a7695219217c7d8ad9f842242ed223e2a1a4 (diff) | |
download | linux-c3fbbf9308cc939663fdfb90334fe344947dd645.tar.gz linux-c3fbbf9308cc939663fdfb90334fe344947dd645.tar.bz2 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>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r-- | arch/arm/kernel/cpuidle.c | 17 |
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; } |