[PATCH 4.14 161/183] ACPI / EC: Restore polling during noirq suspend/resume phases

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>


[ Upstream commit 3cd091a773936c54344a519f7ee1379ccb620bee ]

Commit 662591461c4b (ACPI / EC: Drop EC noirq hooks to fix a
regression) modified the ACPI EC driver so that it doesn't switch
over to busy polling mode during noirq stages of system suspend and
resume in an attempt to fix an issue resulting from that behavior.

However, that modification introduced a system resume regression on
Thinkpad X240, so make the EC driver switch over to the polling mode
during noirq stages of system suspend and resume again, which
effectively reverts the problematic commit.

Fixes: 662591461c4b (ACPI / EC: Drop EC noirq hooks to fix a regression)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197863
Reported-by: Markus Demleitner <m@xxxxxxx>
Tested-by: Markus Demleitner <m@xxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/acpi/ec.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1927,6 +1927,9 @@ static int acpi_ec_suspend_noirq(struct
 	    ec->reference_count >= 1)
 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_DISABLE);
 
+	if (acpi_sleep_no_ec_events())
+		acpi_ec_enter_noirq(ec);
+
 	return 0;
 }
 
@@ -1934,6 +1937,9 @@ static int acpi_ec_resume_noirq(struct d
 {
 	struct acpi_ec *ec = acpi_driver_data(to_acpi_device(dev));
 
+	if (acpi_sleep_no_ec_events())
+		acpi_ec_leave_noirq(ec);
+
 	if (ec_no_wakeup && test_bit(EC_FLAGS_STARTED, &ec->flags) &&
 	    ec->reference_count >= 1)
 		acpi_set_gpe(NULL, ec->gpe, ACPI_GPE_ENABLE);