commit 573b638158029898caf9470c8214b7ddd29751e3 upstream.

Section 4.7.3.1.1 (PM1 Status Registers) of version 4.0 of
the ACPI spec concerning PCIEXP_WAKE_STS points out in
in the final note field in table 4-11 that if this bit is
set to 1 and the system is put into a sleeping state then
the system will not automatically wake.

This bit gets set by hardware to indicate that the system
woke up due to a PCI Express wakeup event, so clear it during
acpi_hw_clear_acpi_status() calls to enable subsequent
resumes to work.

BugLink: http://bugs.launchpad.net/bugs/613381

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Folklore suggested that such systems existed
in the pre-history of ACPI.

However, we removed the SCI_EN polling loop from
acpi_hw_set_mode() in b430acbd7c4b919886fa7fd92eeb7a695f1940d3
because it delayed resume by 3 seconds on boxes
that refused to set SCI_EN.

Matthew removed the call to acpi_enable() from
the suspend resume path.

James found a modern system that still needs to be polled
upon boot.

So here we restore the workaround, except that we
put it in acpi_enable() rather than the low level
acpi_hw_set_mode().

https://bugzilla.kernel.org/show_bug.cgi?id=16271

Signed-off-by: Len Brown <len.brown@intel.com>

This feature is optional and is enabled if the BIOS requests any
Windows OSI strings. It can also be enabled by the host OS.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

To prevent accidental deep sleeps, limit the maximum time that
Sleep() will sleep. Configurable, default maximum is two seconds.
ACPICA bugzilla 854.

http://www.acpica.org/bugzilla/show_bug.cgi?id=854

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

While developing the GPE reference counting code we overlooked the
fact that acpi_ev_update_gpes() could have enabled GPEs before
acpi_ev_initialize_gpe_block() was called.  As a result, some GPEs
are enabled twice during the initialization.

To fix this issue avoid calling acpi_enable_gpe() from
acpi_ev_initialize_gpe_block() for the GPEs that have nonzero
runtime reference counters.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPICA uses acpi_hw_write_gpe_enable_reg() to re-enable a GPE after
an event signaled by it has been handled.  However, this function
writes the entire GPE enable mask to the GPE's enable register which
may not be correct.  Namely, if one of the other GPEs in the same
register was previously enabled by acpi_enable_gpe() and subsequently
disabled using acpi_set_gpe(), acpi_hw_write_gpe_enable_reg() will
re-enable it along with the target GPE.

To fix this issue rework acpi_hw_write_gpe_enable_reg() so that it
calls acpi_hw_low_set_gpe() with a special action value,
ACPI_GPE_COND_ENABLE, that will make it only enable the GPE if the
corresponding bit in its register's enable_for_run mask is set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPICA uses acpi_ev_enable_gpe() for enabling GPEs at the low level,
which is incorrect, because this function only enables the GPE if the
corresponding bit in its enable register's enable_for_run mask is set.
This causes acpi_set_gpe() to work incorrectly if used for enabling
GPEs that were not previously enabled with acpi_enable_gpe().  As a
result, among other things, wakeup-only GPEs are never enabled by
acpi_enable_wakeup_device(), so the devices that use them are unable
to wake up the system.

To fix this issue remove acpi_ev_enable_gpe() and its counterpart
acpi_ev_disable_gpe() and replace acpi_hw_low_disable_gpe() with
acpi_hw_low_set_gpe() that will be used instead to manipulate GPE
enable bits at the low level.  Make the users of acpi_ev_enable_gpe()
and acpi_ev_disable_gpe() call acpi_hw_low_set_gpe() instead and
make sure that GPE enable masks are only updated by acpi_enable_gpe()
and acpi_disable_gpe() when GPE reference counters change from 0
to 1 and from 1 to 0, respectively.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

In quite a few places ACPICA needs to compute a GPE enable mask with
only one bit, corresponding to a given GPE, set.  Currently, that
computation is always open coded which leads to unnecessary code
duplication.  Fix this by introducing a helper function for computing
one-bit GPE enable masks and using it where appropriate.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>