linux-toradex.git/drivers/acpi/scan.c, branch v3.4.2 Linux kernel for Apalis and Colibri modules ACPI / PCI / PM: Fix device PM regression related to D3hot/D3cold 2012-05-17T23:16:16+00:00 Rafael J. Wysocki rjw@sisk.pl 2012-05-17T22:39:35+00:00 5c7dd710f691d1b44c39e32d2f05b4286ff51f99 Commit 1cc0c998fdf2 ("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: rocko <rockorequin@hotmail.com> Reported-by: Cristian Rodríguez <crrodriguez@opensuse.org> Reported-and-tested-by: Peter <lekensteyn@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Commit 1cc0c998fdf2 ("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: rocko <rockorequin@hotmail.com>
Reported-by: Cristian Rodríguez <crrodriguez@opensuse.org>
Reported-and-tested-by: Peter <lekensteyn@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ACPI: Fix D3hot v D3cold confusion 2012-05-05T05:19:52+00:00 Lin Ming ming.m.lin@intel.com 2012-04-23T01:03:49+00:00 1cc0c998fdf2cb665d625fb565a0d6db5c81c639 Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot in some places, but D3cold in other places. After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD; and all references to D3hot use ACPI_STATE_D3_HOT. ACPI's _PR3 method is used to enter both D3hot and D3cold states. What distinguishes D3hot from D3cold is the presence _PR3 (Power Resources for D3hot) If these resources are all ON, then the state is D3hot. If _PR3 is not present, or all _PR0 resources for the devices are OFF, then the state is D3cold. This patch applies after Linux-3.4-rc1. A future syntax cleanup may remove ACPI_STATE_D3 to emphasize that it always means ACPI_STATE_D3_COLD. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Aaron Lu <aaron.lu@amd.com> Signed-off-by: Len Brown <len.brown@intel.com> 
Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot
in some places, but D3cold in other places.

After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD;
and all references to D3hot use ACPI_STATE_D3_HOT.

ACPI's _PR3 method is used to enter both D3hot and D3cold states.
What distinguishes D3hot from D3cold is the presence _PR3
(Power Resources for D3hot)  If these resources are all ON,
then the state is D3hot.  If _PR3 is not present,
or all _PR0 resources for the devices are OFF,
then the state is D3cold.

This patch applies after Linux-3.4-rc1.
A future syntax cleanup may remove ACPI_STATE_D3
to emphasize that it always means ACPI_STATE_D3_COLD.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Merge branch 'd3' into release 2012-03-30T20:21:26+00:00 Len Brown len.brown@intel.com 2012-03-30T20:21:26+00:00 ec612fcf43e09f5e05d37baf4d3f138b3fcc2f3d Conflicts: drivers/acpi/sleep.c This was a text conflict between a2ef5c4fd44ce3922435139393b89f2cce47f576 (ACPI: Move module parameter gts and bfs to sleep.c) which added #include <linux/module.h> and b24e5098853653554baf6ec975b9e855f3d6e5c0 (ACPI, PCI: Move acpi_dev_run_wake() to ACPI core) which added #include <linux/pm_runtime.h> The resolution was to take them both. Signed-off-by: Len Brown <len.brown@intel.com> 
Conflicts:
	drivers/acpi/sleep.c

This was a text conflict between
a2ef5c4fd44ce3922435139393b89f2cce47f576
(ACPI: Move module parameter gts and bfs to sleep.c)

which added #include <linux/module.h>

and

b24e5098853653554baf6ec975b9e855f3d6e5c0
(ACPI, PCI: Move acpi_dev_run_wake() to ACPI core)

which added #include <linux/pm_runtime.h>

The resolution was to take them both.

Signed-off-by: Len Brown <len.brown@intel.com>
ACPI: Clean redundant codes in scan.c 2012-03-30T08:00:16+00:00 Alex He alex.he@amd.com 2012-02-21T08:58:10+00:00 37239978778806ecba54da60676abb46870acebb Clean the redundant codes of apci_bus_get_power_flags(). Signed-off-by: Alex He <alex.he@amd.com> Signed-off-by: Len Brown <len.brown@intel.com> 
Clean the redundant codes of apci_bus_get_power_flags().

Signed-off-by: Alex He <alex.he@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI: Introduce ACPI D3_COLD state support 2012-03-30T05:47:00+00:00 Zhang Rui rui.zhang@intel.com 2012-03-29T06:09:38+00:00 3ebc81b8937d2bc1d0d0064bed29434dfce490aa If a device has _PR3, it means the device supports D3_COLD. Add the ability to validate and enter D3_COLD state in ACPI. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> 
If a device has _PR3, it means the device supports D3_COLD.
Add the ability to validate and enter D3_COLD state in ACPI.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI: use kstrdup() 2011-11-07T00:13:44+00:00 Thomas Meyer thomas@m3y3r.de 2011-08-06T09:32:56+00:00 581de59e8dff8eaa52809e768a585e9ef336aa4a Use kstrdup rather than duplicating its implementation The semantic patch that makes this output is available in scripts/coccinelle/api/kstrdup.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/ Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Len Brown <len.brown@intel.com> 
 Use kstrdup rather than duplicating its implementation

 The semantic patch that makes this output is available
 in scripts/coccinelle/api/kstrdup.cocci.

 More information about semantic patching is available at
 http://coccinelle.lip6.fr/

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI / PM: Avoid infinite recurrence while registering power resources 2011-04-26T09:33:18+00:00 Rafael J. Wysocki rjw@sisk.pl 2011-04-26T09:33:18+00:00 7bed50c5edf5cba8dd515a31191cbfb6065ddc85 There is at least one BIOS with a DSDT containing a power resource object with a _PR0 entry pointing back to that power resource. In consequence, while registering that power resource acpi_bus_get_power_flags() sees that it depends on itself and tries to register it again, which leads to an infinitely deep recurrence. This problem was introduced by commit bf325f9538d8c89312be305b9779e (ACPI / PM: Register power resource devices as soon as they are needed). To fix this problem use the observation that power resources cannot be power manageable and prevent acpi_bus_get_power_flags() from being called for power resource objects. References: https://bugzilla.kernel.org/show_bug.cgi?id=31872 Reported-and-tested-by: Pascal Dormeau <pdormeau@free.fr> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <lenb@kernel.org> Cc: stable@kernel.org 
There is at least one BIOS with a DSDT containing a power resource
object with a _PR0 entry pointing back to that power resource.  In
consequence, while registering that power resource
acpi_bus_get_power_flags() sees that it depends on itself and tries
to register it again, which leads to an infinitely deep recurrence.
This problem was introduced by commit bf325f9538d8c89312be305b9779e
(ACPI / PM: Register power resource devices as soon as they are
needed).

To fix this problem use the observation that power resources cannot
be power manageable and prevent acpi_bus_get_power_flags() from
being called for power resource objects.

References: https://bugzilla.kernel.org/show_bug.cgi?id=31872
Reported-and-tested-by: Pascal Dormeau <pdormeau@free.fr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <lenb@kernel.org>
Cc: stable@kernel.org
ACPI: Remove the wakeup.run_wake_count device field 2011-02-24T18:58:53+00:00 Rafael J. Wysocki rjw@sisk.pl 2011-02-08T22:40:37+00:00 5190726765b40774c069e187a958e10ccd970e65 The wakeup.run_wake_count ACPI device field is only used by the PCI runtime PM code to "protect" devices from being prepared for generating wakeup signals more than once in a row. However, it really doesn't provide any protection, because (1) all of the functions it is supposed to protect use their own reference counters effectively ensuring that the device will be set up for generating wakeup signals just once and (2) the PCI runtime PM code uses wakeup.run_wake_count in a racy way, since nothing prevents acpi_dev_run_wake() from being called concurrently from two different threads for the same device. Remove the wakeup.run_wake_count ACPI device field which is unnecessary, confusing and used in a wrong way. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> 
The wakeup.run_wake_count ACPI device field is only used by the PCI
runtime PM code to "protect" devices from being prepared for
generating wakeup signals more than once in a row.  However, it
really doesn't provide any protection, because (1) all of the
functions it is supposed to protect use their own reference counters
effectively ensuring that the device will be set up for generating
wakeup signals just once and (2) the PCI runtime PM code uses
wakeup.run_wake_count in a racy way, since nothing prevents
acpi_dev_run_wake() from being called concurrently from two different
threads for the same device.

Remove the wakeup.run_wake_count ACPI device field which is
unnecessary, confusing and used in a wrong way.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ACPI: Drop device flag wake_capable 2011-01-12T10:06:01+00:00 Rafael J. Wysocki rjw@sisk.pl 2011-01-06T22:41:27+00:00 d57d09a480e1db38eeee7629c81289b00f338a15 The wake_capable ACPI device flag is not necessary, because it is only used in scan.c for recording the information that _PRW is present for the given device. That information is only used by acpi_add_single_object() to decide whether or not to call acpi_bus_get_wakeup_device_flags(), so the flag may be dropped if the _PRW check is moved to acpi_bus_get_wakeup_device_flags(). Moreover, acpi_bus_get_wakeup_device_flags() always returns 0, so it really should be void. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com> 
The wake_capable ACPI device flag is not necessary, because it is
only used in scan.c for recording the information that _PRW is
present for the given device.  That information is only used by
acpi_add_single_object() to decide whether or not to call
acpi_bus_get_wakeup_device_flags(), so the flag may be dropped
if the _PRW check is moved to acpi_bus_get_wakeup_device_flags().
Moreover, acpi_bus_get_wakeup_device_flags() always returns 0,
so it really should be void.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI: Always check if _PRW is present before trying to evaluate it 2011-01-12T10:05:50+00:00 Rafael J. Wysocki rjw@sisk.pl 2011-01-06T22:40:00+00:00 86e4e20e8a5301ff7104a4f40f35fd5bee408186 Before evaluating _PRW for devices that are reported as inactive or not present by their _STA control methods we should check if those methods are actually present (otherwise the evaulation of _PRW will obviously fail and a scary message will be printed unnecessarily). Reported-by: Andreas Mohr <andi@lisas.de> Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com> 
Before evaluating _PRW for devices that are reported as inactive or
not present by their _STA control methods we should check if those
methods are actually present (otherwise the evaulation of _PRW will
obviously fail and a scary message will be printed unnecessarily).

Reported-by: Andreas Mohr <andi@lisas.de>
Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>