Currently we have valid flag to represent if this ACPI device power
state is valid. A device power state is valid does not necessarily
mean we, as OSPM, has a mean to put the device into that power state,
e.g. D3 cold is always a valid power state for any ACPI device, but if
there is no _PS3 or _PRx for this device, we can't really put that
device into D3 cold power state. The same is true for D0 power state.
So here comes the os_accessible flag, which is only set if the device
has provided us the required means to put it into that power state,
e.g. if we have _PS3 or _PRx, we can put the device into D3 cold state
and thus, D3 cold power state's os_accessible flag will be set in this
case.
And a new wrapper inline function is added to be used to check if
firmware has provided us a way to power off the device during runtime.
Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
---
v2:
Rename swset to os_accessible as suggested by Rafael Wysocki.
Fold patch 2 into patch 1 as suggested by Rafael Wysocki.
drivers/acpi/scan.c | 9 ++++++++-
include/acpi/acpi_bus.h | 6 ++++++
2 files changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 3c646e6..f250c5b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1062,8 +1062,10 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
* D3hot is only valid if _PR3 present.
*/
if (ps->resources.count ||
- (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT))
+ (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT)) {
ps->flags.valid = 1;
+ ps->flags.os_accessible = 1;
+ }
ps->power = -1; /* Unknown - driver assigned */
ps->latency = -1; /* Unknown - driver assigned */
@@ -1079,6 +1081,11 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;
+ /* Presence of _PS3 or _PRx means we can put the device into D3 cold */
+ if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||
+ device->power.flags.power_resources)
+ device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;
+
acpi_bus_init_power(device);
return 0;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ce77cd7..644d941 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -201,6 +201,7 @@ struct acpi_device_power_flags {
struct acpi_device_power_state {
struct {
u8 valid:1;
+ u8 os_accessible:1;
u8 explicit_set:1; /* _PSx present? */
u8 reserved:6;
} flags;
@@ -500,6 +501,11 @@ static inline bool acpi_device_can_wakeup(struct acpi_device *adev)
return adev->wakeup.flags.valid;
}
+static inline bool acpi_device_can_poweroff(struct acpi_device *adev)
+{
+ return adev->power.states[ACPI_STATE_D3_COLD].flags.os_accessible;
+}
+
#else /* CONFIG_ACPI */
static inline int register_acpi_bus_type(void *bus) { return 0; }
--
1.7.12.4
--
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