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 4.9-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-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 662591461c4b9a1e3b9b159dbf37648a585ebaae Mon Sep 17 00:00:00 2001 From: Lv Zheng <lv.zheng@xxxxxxxxx> Date: Wed, 12 Jul 2017 11:09:09 +0800 Subject: ACPI / EC: Drop EC noirq hooks to fix a regression From: Lv Zheng <lv.zheng@xxxxxxxxx> 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@xxxxxxxxx> Tested-by: Gjorgji Jankovski <j.gjorgji@xxxxxxxxx> Tested-by: Damjan Georgievski <gdamjan@xxxxxxxxx> Tested-by: Fernando Chaves <nanochaves@xxxxxxxxx> Tested-by: Tomislav Ivek <tomislav.ivek@xxxxxxxxx> Tested-by: Denis P. <theoriginal.skullburner@xxxxxxxxx> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/ec.c | 19 ------------------- 1 file changed, 19 deletions(-) --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -1865,24 +1865,6 @@ 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 = @@ -1904,7 +1886,6 @@ 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 lv.zheng@xxxxxxxxx are queue-4.9/revert-acpi-ec-enable-event-freeze-mode...-to-fix-a-regression.patch queue-4.9/acpi-ec-drop-ec-noirq-hooks-to-fix-a-regression.patch