diff options
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-07-04 13:22:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-21 18:21:29 -0700
commit2757f8d630ae099abc7d51b7b09de76a33876bf4 (patch)
parent22a5fdfc36cd18abfd421699e9076307fa54dae4 (diff)
ACPI / PM: Fix corner case in acpi_bus_update_power()
commit 91bdad0b6237c25a7bf8fd4604d0cc64a2005a23 upstream. The role of acpi_bus_update_power() is to update the given ACPI device object's power.state field to reflect the current physical state of the device (as inferred from the configuration of power resources and _PSC, if available). For this purpose it calls acpi_device_set_power() that should update the power resources' reference counters and set power.state as appropriate. However, that doesn't work if the "new" state is D1, D2 or D3hot and the the current value of power.state means D3cold, because in that case acpi_device_set_power() will refuse to transition the device from D3cold to non-D0. To address this problem, make acpi_bus_update_power() call acpi_power_transition() directly to update the power resources' reference counters and only use acpi_device_set_power() to put the device into D0 if the current physical state of it cannot be determined. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 31c217a4283..553527c2532 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -324,14 +324,27 @@ int acpi_bus_update_power(acpi_handle handle, int *state_p)
if (result)
return result;
- if (state == ACPI_STATE_UNKNOWN)
+ if (state == ACPI_STATE_UNKNOWN) {
state = ACPI_STATE_D0;
- result = acpi_device_set_power(device, state);
- if (!result && state_p)
+ result = acpi_device_set_power(device, state);
+ if (result)
+ return result;
+ } else {
+ if (device->power.flags.power_resources) {
+ /*
+ * We don't need to really switch the state, bu we need
+ * to update the power resources' reference counters.
+ */
+ result = acpi_power_transition(device, state);
+ if (result)
+ return result;
+ }
+ device->power.state = state;
+ }
+ if (state_p)
*state_p = state;
- return result;
+ return 0;