diff options
| author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-04-26 11:33:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-05-02 09:19:43 -0700 |
| commit | 2aaf1f781cb77812e5d9678d7b126ec13cebf283 (patch) | |
| tree | 2440ef4d3ccb079187996bc7e9ca9be942d68531 /drivers/acpi/scan.c | |
| parent | 642dbe81ce8c46e26a190ab641633858961b9ad4 (diff) | |
ACPI / PM: Avoid infinite recurrence while registering power resources
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 <pdormeau@free.fr>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/acpi/scan.c')
| -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 b99e6249460..8eee69faf23 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -944,6 +944,10 @@ 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)) |