1 From 1d672ef324e78a467603ef55aa4558cac9f895ba Mon Sep 17 00:00:00 2001
2 From: Holger Macht <hmacht@suse.de>
3 Date: Tue, 20 Jan 2009 12:18:24 +0100
4 Subject: ACPI: dock: Don't eval _STA on every show_docked sysfs read
6 From: Holger Macht <hmacht@suse.de>
8 commit fc5a9f8841ee87d93376ada5d73117d4d6a373ea upstream.
10 Some devices trigger a DEVICE_CHECK on every evalutation of _STA. This
11 can also be seen in commit 8b59560a3baf2e7c24e0fb92ea5d09eca92805db
12 (ACPI: dock: avoid check _STA method). If an undock is processed, the
13 dock driver sends a uevent and userspace might read the show_docked
14 property in sysfs. This causes an evaluation of _STA of the particular
15 device which causes the dock driver to immediately dock again.
17 In any case, evaluation of _STA (show_docked) does not necessarily mean
18 that we are docked, so check with the internal device structure.
20 http://bugzilla.kernel.org/show_bug.cgi?id=12360
22 Signed-off-by: Holger Macht <hmacht@suse.de>
23 Signed-off-by: Len Brown <len.brown@intel.com>
24 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
27 drivers/acpi/dock.c | 8 +++++++-
28 1 file changed, 7 insertions(+), 1 deletion(-)
30 --- a/drivers/acpi/dock.c
31 +++ b/drivers/acpi/dock.c
32 @@ -854,8 +854,14 @@ fdd_out:
33 static ssize_t show_docked(struct device *dev,
34 struct device_attribute *attr, char *buf)
36 - return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
37 + struct acpi_device *tmp;
39 + struct dock_station *dock_station = *((struct dock_station **)
40 + dev->platform_data);
42 + if (ACPI_SUCCESS(acpi_bus_get_device(dock_station->handle, &tmp)))
43 + return snprintf(buf, PAGE_SIZE, "1\n");
44 + return snprintf(buf, PAGE_SIZE, "0\n");
46 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);