Commit fc5a9f88 authored Jan 20, 2009 by Holger Macht Committed by Len Brown Feb 06, 2009

ACPI: dock: Don't eval _STA on every show_docked sysfs read

Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
can also be seen in commit 8b59560a
(ACPI: dock: avoid check _STA method).  If an undock is processed, the
dock driver sends a uevent and userspace might read the show_docked
property in sysfs. This causes an evaluation of _STA of the particular
device which causes the dock driver to immediately dock again.

In any case, evaluation of _STA (show_docked) does not necessarily mean
that we are docked, so check with the internal device structure.

http://bugzilla.kernel.org/show_bug.cgi?id=12360



Signed-off-by: Holger Macht <hmacht@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

parent 9e3a9d1e

drivers/acpi/dock.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -855,10 +855,14 @@ fdd_out:
		static ssize_t show_docked(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct acpi_device *tmp;

		struct dock_station dock_station = ((struct dock_station **)
		dev->platform_data);
		return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));

		if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
		return snprintf(buf, PAGE_SIZE, "1\n");
		return snprintf(buf, PAGE_SIZE, "0\n");
		}
		static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);

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