linux-imx

ACPICA: Clear status of GPEs before enabling them

Commit 18996f2db918 ("ACPICA: Events: Stop unconditionally clearing
ACPI IRQs during suspend/resume") was added to stop clearing event
status bits unconditionally in the system-wide suspend and resume
paths. This was done because of an issue with a laptop lid appaering
to be closed even when it was used to wake up the system from suspend
(see https://bugzilla.kernel.org/show_bug.cgi?id=196249), which
happened because event status bits were cleared unconditionally on
system resume. Though this change fixed the issue in the resume path,
it introduced regressions in a few suspend paths.

First regression was reported and fixed in the S5 entry path by commit
fa85015c0d95 ("ACPICA: Clear status of all events when entering S5").
Next regression was reported and fixed for all legacy sleep paths by
commit f317c7dc12b7 ("ACPICA: Clear status of all events when entering
sleep states").  However, there still is a suspend-to-idle regression,
since suspend-to-idle does not follow the legacy sleep paths.

In the suspend-to-idle case, wakeup is enabled as part of device
suspend.  If the status bits of wakeup GPEs are set when they are
enabled, it causes a premature system wakeup to occur.

To address that problem, partially revert commit 18996f2db918 to
restore GPE status bits clearing before the GPE is enabled in
acpi_ev_enable_gpe().

Fixes: 18996f2db918 ("ACPICA: Events: Stop unconditionally clearing ACPI IRQs during suspend/resume")
Signed-off-by: Furquan Shaikh <furquan@google.com>
Cc: 4.17+ <stable@vger.kernel.org> # 4.17+
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>