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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-08-23 23:19:57 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-08-30 03:05:29 +0200 |
| commit | dc2251bf98c66db3f4e055b751968f0871037ae4 (patch) | |
| tree | a18ffbaae6dc1e54069fd19ebcfc93b88d42a9fa /drivers/acpi | |
| parent | 84dc4141f0353bada6af53d32730f3e47e579bc0 (diff) | |
| download | linux-dc2251bf98c66db3f4e055b751968f0871037ae4.tar.bz2 | |
cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol
On some architectures the first (index 0) idle state is a polling
one and it doesn't really save energy, so there is the
CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of
cpuidle code to avoid using that state.
However, this makes the code rather hard to follow. It is better
to explicitly avoid the polling state, so add a new cpuidle state
flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code
check that flag for the first state instead of using the
CPUIDLE_DRIVER_STATE_START symbol.
In the ACPI processor driver that cannot always rely on the state
flags (like before the states table has been set up) define
a new internal symbol ACPI_IDLE_STATE_START equivalent to the
CPUIDLE_DRIVER_STATE_START one and drop the latter.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/processor_idle.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 5c8aa9cf62d7..39a01ea7a46d 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -48,6 +48,8 @@ #define _COMPONENT ACPI_PROCESSOR_COMPONENT ACPI_MODULE_NAME("processor_idle"); +#define ACPI_IDLE_STATE_START (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0) + static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER; module_param(max_cstate, uint, 0000); static unsigned int nocst __read_mostly; @@ -761,7 +763,7 @@ static int acpi_idle_enter(struct cpuidle_device *dev, if (cx->type != ACPI_STATE_C1) { if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) { - index = CPUIDLE_DRIVER_STATE_START; + index = ACPI_IDLE_STATE_START; cx = per_cpu(acpi_cstate[index], dev->cpu); } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) { if (cx->bm_sts_skip || !acpi_idle_bm_check()) { @@ -813,7 +815,7 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev, static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, struct cpuidle_device *dev) { - int i, count = CPUIDLE_DRIVER_STATE_START; + int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; if (max_cstate == 0) @@ -840,7 +842,7 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr, static int acpi_processor_setup_cstates(struct acpi_processor *pr) { - int i, count = CPUIDLE_DRIVER_STATE_START; + int i, count = ACPI_IDLE_STATE_START; struct acpi_processor_cx *cx; struct cpuidle_state *state; struct cpuidle_driver *drv = &acpi_idle_driver; @@ -1291,7 +1293,7 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr) return -EINVAL; drv->safe_state_index = -1; - for (i = CPUIDLE_DRIVER_STATE_START; i < CPUIDLE_STATE_MAX; i++) { + for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) { drv->states[i].name[0] = '\0'; drv->states[i].desc[0] = '\0'; } |