ACPI / EC: Drop EC noirq hooks to fix a regression
authorLv Zheng <lv.zheng@intel.com>
Wed, 12 Jul 2017 03:09:09 +0000 (11:09 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jul 2017 22:08:04 +0000 (15:08 -0700)
commitb2966b109b1a2c23e626ad35fc03d4a52efd1aa4
tree05301913758c7fbaa3223b16bbb2b1f366c5b754
parentec469b5e2aafdcedbc80d9a7a8a4fa8632e584e3
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>
drivers/acpi/ec.c