From 9ed411c06dd1cdf6171b992f68c37bc2d66054f9 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 4 Jul 2019 01:02:49 +0200 Subject: ACPI: PM: Unexport acpi_device_get_power() Using acpi_device_get_power() outside of ACPI device initialization and ACPI sysfs is problematic due to the way in which power resources are handled by it, so unexport it and add a paragraph explaining the pitfalls to its kerneldoc comment. Signed-off-by: Rafael J. Wysocki Reviewed-by: Mika Westerberg --- drivers/acpi/device_pm.c | 6 +++++- drivers/acpi/internal.h | 7 +++++++ 2 files changed, 12 insertions(+), 1 deletion(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index e54956ae93d3..81eb15a0cc42 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -53,6 +53,11 @@ const char *acpi_power_state_string(int state) * This function does not update the device's power.state field, but it may * update its parent's power.state field (when the parent's power state is * unknown and the device's power state turns out to be D0). + * + * Also, it does not update power resource reference counters to ensure that + * the power state returned by it will be persistent and it may return a power + * state shallower than previously set by acpi_device_set_power() for @device + * (if that power state depends on any power resources). */ int acpi_device_get_power(struct acpi_device *device, int *state) { @@ -118,7 +123,6 @@ int acpi_device_get_power(struct acpi_device *device, int *state) return 0; } -EXPORT_SYMBOL(acpi_device_get_power); static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state) { diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index f6157d4d637a..f4c2fe6be4f2 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -139,8 +139,15 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state); int acpi_power_on_resources(struct acpi_device *device, int state); int acpi_power_transition(struct acpi_device *device, int state); +/* -------------------------------------------------------------------------- + Device Power Management + -------------------------------------------------------------------------- */ +int acpi_device_get_power(struct acpi_device *device, int *state); int acpi_wakeup_device_init(void); +/* -------------------------------------------------------------------------- + Processor + -------------------------------------------------------------------------- */ #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC void acpi_early_processor_set_pdc(void); #else -- cgit v1.2.3