Patch "ACPI / EC: Drop EC noirq hooks to fix a regression" has been added to the 4.12-stable tree

This is a note to let you know that I've just added the patch titled

ACPI / EC: Drop EC noirq hooks to fix a regression

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
acpi-ec-drop-ec-noirq-hooks-to-fix-a-regression.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Lv Zheng <[email protected]>
Date: Wed, 12 Jul 2017 11:09:09 +0800
Subject: ACPI / EC: Drop EC noirq hooks to fix a regression

From: Lv Zheng <[email protected]>

commit 662591461c4b9a1e3b9b159dbf37648a585ebaae upstream.

According to bug reports, although the busy polling mode can make noirq stages execute faster, it causes abnormal fan blowing up after system resume (see the first link below for a video demonstration) on Lenovo ThinkPad X1 Carbon - the 5th Generation. The problem can be fixed by upgrading the EC firmware on that machine.

However, many reporters confirm that the problem can be fixed by stopping busy polling during suspend/resume and for some of them upgrading the EC firmware is not an option.

For this reason, drop the noirq stage hooks from the EC driver to fix the regression.

---
 drivers/acpi/ec.c |   19 -------------------
 1 file changed, 19 deletions(-)

@@ -1812,24 +1812,6 @@ error:
 }
 
 #ifdef CONFIG_PM_SLEEP
-static int acpi_ec_suspend_noirq(struct device *dev)
-{
-	struct acpi_ec *ec =
-		acpi_driver_data(to_acpi_device(dev));
-
-	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));
-
-	acpi_ec_leave_noirq(ec);
-	return 0;
-}
-
 static int acpi_ec_suspend(struct device *dev)
 {
 	struct acpi_ec *ec =

@@ -1851,7 +1833,6 @@ static int acpi_ec_resume(struct device
 #endif
 
 static const struct dev_pm_ops acpi_ec_pm = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq)
 	SET_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend, acpi_ec_resume)
 };
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/revert-acpi-ec-enable-event-freeze-mode...-to-fix-a-regression.patch queue-4.12/acpi-ec-drop-ec-noirq-hooks-to-fix-a-regression.patch