From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> mainline inclusion from mainline-v5.3-rc3 commit 42787ed79638 category: bugfix bugzilla: 17645 CVE: NA ------------------------------------------------- Commit f850a48a0799 ("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: f850a48a0799 ("ACPI: PM: Allow transitions to D0 to occur in special cases") Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Reported-by: Mario Limonciello <mario.limonciello@dell.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Tested-by: Mario Limonciello <mario.limonciello@dell.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/acpi/device_pm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index 6687729..19a96b4 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -235,13 +235,15 @@ int acpi_device_set_power(struct acpi_device *device, int state) if (device->power.flags.power_resources) result = acpi_power_transition(device, target_state); } else { + int cur_state = device->power.state; + if (device->power.flags.power_resources) { result = acpi_power_transition(device, ACPI_STATE_D0); if (result) goto end; } - if (device->power.state == ACPI_STATE_D0) { + if (cur_state == ACPI_STATE_D0) { int psc; /* Nothing to do here if _PSC is not present. */ -- 1.8.3