From 7cd8407d53ef5fb0280fcbe34f42311472f90feb Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 5 Jun 2013 14:01:19 +0200 Subject: [PATCH] ACPI / PM: Do not execute _PS0 for devices without _PSC during initialization Commit b378549 (ACPI / PM: Do not power manage devices in unknown initial states) added code to force devices without _PSC, but having _PS0 defined in the ACPI namespace, into ACPI power state D0 by executing _PS0 for them. That turned out to break Toshiba P870-303, however, so revert that code. References: https://bugzilla.kernel.org/show_bug.cgi?id=58201 Reported-and-tested-by: Jerome Cantenot Tracked-down-by: Lan Tianyu Cc: 3.9+ Signed-off-by: Rafael J. Wysocki --- drivers/acpi/device_pm.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c index bc493aa3af19..318fa32a141e 100644 --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -278,11 +278,13 @@ int acpi_bus_init_power(struct acpi_device *device) if (result) return result; } else if (state == ACPI_STATE_UNKNOWN) { - /* No power resources and missing _PSC? Try to force D0. */ + /* + * No power resources and missing _PSC? Cross fingers and make + * it D0 in hope that this is what the BIOS put the device into. + * [We tried to force D0 here by executing _PS0, but that broke + * Toshiba P870-303 in a nasty way.] + */ state = ACPI_STATE_D0; - result = acpi_dev_pm_explicit_set(device, state); - if (result) - return result; } device->power.state = state; return 0; -- 2.20.1