Commit 9f29ab11 authored Jun 04, 2013 by Aaron Lu Committed by Rafael J. Wysocki Jun 05, 2013

ACPI / scan: do not match drivers against objects having scan handlers

With the introduction of ACPI scan handlers, an ACPI device object
with an ACPI scan handler attached to it must not be bound to an ACPI
driver any more.  Therefore it doesn't make sense to match those
ACPI device objects against a newly registered ACPI driver in
acpi_bus_match(), so make that function return 0 if the device
object passed to it has an ACPI scan handler attached.

This also addresses a regression related to a broken ACPI table in
the BIOS, where it has defined a _ROM method under the PCI root
bridge object.  This causes the video module to treat that object
as a display controller device (since only display devices are
supposed to have a _ROM method defined according to the ACPI spec).
As a result, the ACPI video driver binds to the PCI root bridge
object and overwrites the previously assigned driver_data field of
it, causing subsequent calls to acpi_get_pci_dev() to fail.

[rjw: Subject and changelog]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58091


Reported-by: Jason Cassell <bluesloth600@gmail.com>
Reported-and-bisected-by: Dmitry S. Demin <dmitryy.demin@gmail.com>
Cc: 3.9+ <stable@kernel.org>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent a98d4f64

drivers/acpi/scan.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -740,6 +740,10 @@ static int acpi_bus_match(struct device dev, struct device_driver drv)
		struct acpi_device *acpi_dev = to_acpi_device(dev);
		struct acpi_driver *acpi_drv = to_acpi_driver(drv);

		/* Skip ACPI device objects with scan handlers attached. */
		if (acpi_dev->handler)
		return 0;

		return acpi_dev->flags.match_driver
		&& !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
		}

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