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authorRafael J. Wysocki2019-07-04 01:02:49 +0200
committerRafael J. Wysocki2019-07-04 10:49:57 +0200
commit9ed411c06dd1cdf6171b992f68c37bc2d66054f9 (patch)
tree320fde60e04aafe80102d9d98706902c454d3c23
parent28ad4b4e3496871ade868c3d0ecf5c53e4a49041 (diff)
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 <rafael.j.wysocki@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-rw-r--r--drivers/acpi/device_pm.c6
-rw-r--r--drivers/acpi/internal.h7
-rw-r--r--include/acpi/acpi_bus.h1
3 files changed, 12 insertions, 2 deletions
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
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 4752ff0a9d9b..e85dc78f6875 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -506,7 +506,6 @@ int acpi_bus_get_status(struct acpi_device *device);
int acpi_bus_set_power(acpi_handle handle, int state);
const char *acpi_power_state_string(int state);
-int acpi_device_get_power(struct acpi_device *device, int *state);
int acpi_device_set_power(struct acpi_device *device, int state);
int acpi_bus_init_power(struct acpi_device *device);
int acpi_device_fix_up_power(struct acpi_device *device);