Commit 42787ed7 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

ACPI: PM: Fix regression in acpi_device_set_power()

Commit f850a48a ("ACPI: PM: Allow transitions to D0 to occur in
special cases") overlooked the fact that acpi_power_transition() may
change the power.state value for the target device and if that
happens, it may confuse acpi_device_set_power() and cause it to
omit the _PS0 evaluation which on some systems is necessary to
change power states of devices from low-power to D0.

Fix that by saving the current value of power.state for the
target device before passing it to acpi_power_transition() and
using the saved value in a subsequent check.

Fixes: f850a48a ("ACPI: PM: Allow transitions to D0 to occur in special cases")
Reported-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
Reported-by: default avatarMario Limonciello <mario.limonciello@dell.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarKai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: default avatarMario Limonciello <mario.limonciello@dell.com>
parent 609488bc
...@@ -232,13 +232,15 @@ int acpi_device_set_power(struct acpi_device *device, int state) ...@@ -232,13 +232,15 @@ int acpi_device_set_power(struct acpi_device *device, int state)
if (device->power.flags.power_resources) if (device->power.flags.power_resources)
result = acpi_power_transition(device, target_state); result = acpi_power_transition(device, target_state);
} else { } else {
int cur_state = device->power.state;
if (device->power.flags.power_resources) { if (device->power.flags.power_resources) {
result = acpi_power_transition(device, ACPI_STATE_D0); result = acpi_power_transition(device, ACPI_STATE_D0);
if (result) if (result)
goto end; goto end;
} }
if (device->power.state == ACPI_STATE_D0) { if (cur_state == ACPI_STATE_D0) {
int psc; int psc;
/* Nothing to do here if _PSC is not present. */ /* Nothing to do here if _PSC is not present. */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment