Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5c7dd710 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

ACPI / PCI / PM: Fix device PM regression related to D3hot/D3cold 

Commit 1cc0c998 ("ACPI: Fix D3hot v D3cold confusion") introduced a
bug in __acpi_bus_set_power() and changed the behavior of
acpi_pci_set_power_state() in such a way that it generally doesn't work
as expected if PCI_D3hot is passed to it as the second argument.

First off, if ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) is passed to
__acpi_bus_set_power() and the explicit_set flag is set for the D3cold
state, the function will try to execute AML method called "_PS4", which
doesn't exist.

Fix this by adding a check to ensure that the name of the AML method
to execute for transitions to ACPI_STATE_D3_COLD is correct in
__acpi_bus_set_power().  Also make sure that the explicit_set flag
for ACPI_STATE_D3_COLD will be set if _PS3 is present and modify
acpi_power_transition() to avoid accessing power resources for
ACPI_STATE_D3_COLD, because they don't exist.

Second, if PCI_D3hot is passed to acpi_pci_set_power_state() as the
target state, the function will request a transition to
ACPI_STATE_D3_HOT instead of ACPI_STATE_D3.  However,
ACPI_STATE_D3_HOT is now only marked as supported if the _PR3 AML
method is defined for the given device, which is rare.  This causes
problems to happen on systems where devices were successfully put
into ACPI D3 by pci_set_power_state(PCI_D3hot) which doesn't work
now.  In particular, some unused graphics adapters are not turned
off as a result.

To fix this issue restore the old behavior of
acpi_pci_set_power_state(), which is to request a transition to
ACPI_STATE_D3 (equal to ACPI_STATE_D3_COLD) if either PCI_D3hot or
PCI_D3cold is passed to it as the argument.

This approach is not ideal, because generally power should not
be removed from devices if PCI_D3hot is the target power state,
but since this behavior is relied on, we have no choice but to
restore it at the moment and spend more time on designing a
better solution in the future.

References: https://bugzilla.kernel.org/show_bug.cgi?id=43228


Reported-by: default avatarrocko <rockorequin@hotmail.com>
Reported-by: default avatarCristian Rodríguez <crrodriguez@opensuse.org>
Reported-and-tested-by: default avatarPeter <lekensteyn@gmail.com>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent eea03647

drivers/acpi/bus.c

+4 −0
Original line number Diff line number Diff line
@@ -250,6 +250,10 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state) 
		return -ENODEV;

	}



	/* For D3cold we should execute _PS3, not _PS4. */

	if (state == ACPI_STATE_D3_COLD)

		object_name[3] = '3';



	/*

	 * Transition Power

	 * ----------------

drivers/acpi/power.c

+6 −3
Original line number Diff line number Diff line
@@ -660,7 +660,7 @@ int acpi_power_on_resources(struct acpi_device *device, int state) 


int acpi_power_transition(struct acpi_device *device, int state)

{

	int result;

	int result = 0;



	if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))

		return -EINVAL;
@@ -679,8 +679,11 @@ int acpi_power_transition(struct acpi_device *device, int state) 
	 * (e.g. so the device doesn't lose power while transitioning).  Then,

	 * we dereference all power resources used in the current list.

	 */

	result = acpi_power_on_list(&device->power.states[state].resources);

	if (!result)

	if (state < ACPI_STATE_D3_COLD)

		result = acpi_power_on_list(

			&device->power.states[state].resources);



	if (!result && device->power.state < ACPI_STATE_D3_COLD)

		acpi_power_off_list(

			&device->power.states[device->power.state].resources);

drivers/acpi/scan.c

+4 −0
Original line number Diff line number Diff line
@@ -908,6 +908,10 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) 
	device->power.states[ACPI_STATE_D3].flags.valid = 1;

	device->power.states[ACPI_STATE_D3].power = 0;



	/* Set D3cold's explicit_set flag if _PS3 exists. */

	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)

		device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;



	acpi_bus_init_power(device);



	return 0;

drivers/pci/pci-acpi.c

+1 −1
Original line number Diff line number Diff line
@@ -223,7 +223,7 @@ static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state) 
		[PCI_D0] = ACPI_STATE_D0,

		[PCI_D1] = ACPI_STATE_D1,

		[PCI_D2] = ACPI_STATE_D2,

		[PCI_D3hot] = ACPI_STATE_D3_HOT,

		[PCI_D3hot] = ACPI_STATE_D3,

		[PCI_D3cold] = ACPI_STATE_D3

	};

	int error = -EINVAL;