ACPI / EC: Restore polling during noirq suspend/resume phases

[ Upstream commit 3cd091a ]

Commit 6625914 (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: 6625914 (ACPI / EC: Drop EC noirq hooks to fix a regression)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197863
Reported-by: Markus Demleitner <[email protected]>
Tested-by: Markus Demleitner <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: rafaeljw

drivers/acpi/ec.c

@@ -1927,13 +1927,19 @@ static int acpi_ec_suspend_noirq(struct device *dev)
 	    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;
 }
 
 static int acpi_ec_resume_noirq(struct device *dev)
 {
 	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);