Commit b2966b10 authored Jul 12, 2017 by Lv Zheng Committed by Greg Kroah-Hartman Jul 27, 2017

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

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.

Fixes: c3a696b6e8f8 (ACPI / EC: Use busy polling mode when GPE is not enabled)
Link: https://youtu.be/9NQ9x-Jm99Q
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196129


Reported-by: Andreas Lindhe <andreas@lindhe.io>
Tested-by: Gjorgji Jankovski <j.gjorgji@gmail.com>
Tested-by: Damjan Georgievski <gdamjan@gmail.com>
Tested-by: Fernando Chaves <nanochaves@gmail.com>
Tested-by: Tomislav Ivek <tomislav.ivek@gmail.com>
Tested-by: Denis P. <theoriginal.skullburner@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent ec469b5e

drivers/acpi/ec.c

+0 −19

Original line number	Diff line number	Diff line
		@@ -1865,24 +1865,6 @@ int __init acpi_ec_ecdt_probe(void)
		}

		#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 =
		@@ -1904,7 +1886,6 @@ static int acpi_ec_resume(struct device *dev)
		#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)
		};