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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-04-26 13:33:18 +0400 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-04-26 13:33:18 +0400 |
| commit | 7bed50c5edf5cba8dd515a31191cbfb6065ddc85 (patch) | |
| tree | 4b945c6f83803a7ab7aa63467466b9a60a99d824 /drivers/acpi | |
| parent | 22110faf8c8e980013790e6a5214de32b3303730 (diff) | |
| download | linux-7bed50c5edf5cba8dd515a31191cbfb6065ddc85.tar.xz | |
ACPI / PM: Avoid infinite recurrence while registering power resources
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
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/scan.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index b136c9c1e531..449c556274c0 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -943,6 +943,10 @@ static int acpi_bus_get_flags(struct acpi_device *device) 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)) |