From 42787ed79638dc7f0f8d5c164caba1e87bfab50f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 1 Aug 2019 01:31:08 +0200 Subject: ACPI: PM: Fix regression in acpi_device_set_power() 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 Reported-by: Mario Limonciello Signed-off-by: Rafael J. Wysocki Tested-by: Kai-Heng Feng Tested-by: Mario Limonciello --- 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 28cffaaf9d82..f616b16c1f0b 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -232,13 +232,15 @@ 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. */ -- cgit v1.2.3