src/patches/suse-2.6.27.31/patches.arch/acpi-dock-don-t-eval-_sta-on-every-show_docked-sysfs-read.patch

   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
   5
   6 From: Holger Macht <hmacht@suse.de>
   7
   8 commit fc5a9f8841ee87d93376ada5d73117d4d6a373ea upstream.
   9
  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.
  16
  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.
  19
  20 http://bugzilla.kernel.org/show_bug.cgi?id=12360
  21
  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>
  25
  26 ---
  27  drivers/acpi/dock.c |    8 +++++++-
  28  1 file changed, 7 insertions(+), 1 deletion(-)
  29
  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)
  35  {
  36 -       return snprintf(buf, PAGE_SIZE, "%d\n", dock_present(dock_station));
  37 +       struct acpi_device *tmp;
  38
  39 +       struct dock_station *dock_station = *((struct dock_station **)
  40 +               dev->platform_data);
  41 +
  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");
  45  }
  46  static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
  47