This is a note to let you know that I've just added the patch titled
ACPI / PM: Avoid infinite recurrence while registering power resources
to the 2.6.38-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-avoid-infinite-recurrence-while-registering-power-resources.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 7bed50c5edf5cba8dd515a31191cbfb6065ddc85 Mon Sep 17 00:00:00 2001
From: Rafael J. Wysocki <[email protected]>
Date: Tue, 26 Apr 2011 11:33:18 +0200
Subject: ACPI / PM: Avoid infinite recurrence while registering power resources
From: Rafael J. Wysocki <[email protected]>
commit 7bed50c5edf5cba8dd515a31191cbfb6065ddc85 upstream.
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 <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Len Brown <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/acpi/scan.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -944,6 +944,10 @@ static int acpi_bus_get_flags(struct acp
if (ACPI_SUCCESS(status))
device->flags.lockable = 1;
+ /* Power resources cannot be power manageable. */
+ if (device->device_type == ACPI_BUS_TYPE_POWER)
+ return 0;
+
/* Presence of _PS0|_PR0 indicates 'power manageable' */
status = acpi_get_handle(device->handle, "_PS0", &temp);
if (ACPI_FAILURE(status))
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.38/acpi-battery-fribble-sysfs-files-from-a-resume-notifier.patch
queue-2.6.38/acpi-pm-avoid-infinite-recurrence-while-registering-power-resources.patch
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