Commit 6931007c authored Nov 07, 2013 by Rafael J. Wysocki

ACPI / scan: Start matching drivers after trying scan handlers



ACPI scan handlers should always be attached to struct acpi_device
objects before any ACPI drivers, but there is a window during which
a driver may be attached to a struct acpi_device before checking if
there is a matching scan handler.  Namely, that will happen if an
ACPI driver module is loaded during acpi_bus_scan() right after
the first namespace walk is complete and before the given device
is processed by the second namespace walk.

To prevent that from happening, set the match_driver flags of
struct acpi_device objects right before running device_attach()
for them in acpi_bus_device_attach().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>

parent 71bba8fa

drivers/acpi/scan.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -1677,7 +1677,6 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,

		void acpi_device_add_finalize(struct acpi_device *device)
		{
		device->flags.match_driver = true;
		dev_set_uevent_suppress(&device->dev, false);
		kobject_uevent(&device->dev.kobj, KOBJ_ADD);
		}
		@@ -1916,8 +1915,12 @@ static acpi_status acpi_bus_device_attach(acpi_handle handle, u32 lvl_not_used,
		return AE_OK;

		ret = acpi_scan_attach_handler(device);
		if (ret)
		return ret > 0 ? AE_OK : AE_CTRL_DEPTH;
		if (ret < 0)
		return AE_CTRL_DEPTH;

		device->flags.match_driver = true;
		if (ret > 0)
		return AE_OK;

		ret = device_attach(&device->dev);
		return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;