This is a note to let you know that I've just added the patch titled
ACPI / PM: Fix corner case in acpi_bus_update_power()
to the 3.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-pm-fix-corner-case-in-acpi_bus_update_power.patch
and it can be found in the queue-3.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 91bdad0b6237c25a7bf8fd4604d0cc64a2005a23 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <[email protected]>
Date: Thu, 4 Jul 2013 13:22:11 +0200
Subject: ACPI / PM: Fix corner case in acpi_bus_update_power()
From: "Rafael J. Wysocki" <[email protected]>
commit 91bdad0b6237c25a7bf8fd4604d0cc64a2005a23 upstream.
The role of acpi_bus_update_power() is to update the given ACPI
device object's power.state field to reflect the current physical
state of the device (as inferred from the configuration of power
resources and _PSC, if available). For this purpose it calls
acpi_device_set_power() that should update the power resources'
reference counters and set power.state as appropriate. However,
that doesn't work if the "new" state is D1, D2 or D3hot and the
the current value of power.state means D3cold, because in that
case acpi_device_set_power() will refuse to transition the device
from D3cold to non-D0.
To address this problem, make acpi_bus_update_power() call
acpi_power_transition() directly to update the power resources'
reference counters and only use acpi_device_set_power() to put
the device into D0 if the current physical state of it cannot
be determined.
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/acpi/device_pm.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -295,14 +295,27 @@ int acpi_bus_update_power(acpi_handle ha
if (result)
return result;
- if (state == ACPI_STATE_UNKNOWN)
+ if (state == ACPI_STATE_UNKNOWN) {
state = ACPI_STATE_D0;
-
- result = acpi_device_set_power(device, state);
- if (!result && state_p)
+ result = acpi_device_set_power(device, state);
+ if (result)
+ return result;
+ } else {
+ if (device->power.flags.power_resources) {
+ /*
+ * We don't need to really switch the state, bu we need
+ * to update the power resources' reference counters.
+ */
+ result = acpi_power_transition(device, state);
+ if (result)
+ return result;
+ }
+ device->power.state = state;
+ }
+ if (state_p)
*state_p = state;
- return result;
+ return 0;
}
EXPORT_SYMBOL_GPL(acpi_bus_update_power);
Patches currently in stable-queue which might be from
[email protected] are
queue-3.9/acpi-ec-add-hp-folio-13-to-ec_dmi_table-in-order-to-skip-dsdt-scan.patch
queue-3.9/acpica-do-not-use-extended-sleep-registers-unless-hw-reduced-bit-is-set.patch
queue-3.9/acpi-pm-fix-corner-case-in-acpi_bus_update_power.patch
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