commit: 7bed50c5edf5cba8dd515a31191cbfb6065ddc85 From: Rafael J. Wysocki <[email protected]> Date: Tue, 26 Apr 2011 11:33:18 +0200 Subject: [PATCH] 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 <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]> Acked-by: Len Brown <[email protected]> Cc: [email protected] --- 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 b136c9c..449c556 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)) _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
