path: root/drivers/acpi/scan.c
diff options
authorRafael J. Wysocki <rjw@sisk.pl>2011-04-26 11:33:18 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-05-02 09:19:43 -0700
commit2aaf1f781cb77812e5d9678d7b126ec13cebf283 (patch)
tree2440ef4d3ccb079187996bc7e9ca9be942d68531 /drivers/acpi/scan.c
parent642dbe81ce8c46e26a190ab641633858961b9ad4 (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')
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))