commit 231f941500 upstream.
Every time I tried to upgrade my laptop from 3.10.x to 4.x I faced an
issue by which the fan would run at full speed upon resume. Bisecting
it showed me the issue was introduced in 3.17 by commit 821d6f0359
(ACPI / sleep: Do not save NVS for new machines to accelerate S3). This
code only affects machines built starting as of 2012, but this Asus
1025C laptop was made in 2012 and apparently needs the NVS data to be
saved, otherwise the CPU's thermal state is not properly reported on
resume and the fan runs at full speed upon resume.
Here's a very simple way to check if such a machine is affected :
# cat /sys/class/thermal/thermal_zone0/temp
55000
( now suspend, wait one second and resume )
# cat /sys/class/thermal/thermal_zone0/temp
0
(and after ~15 seconds the fan starts to spin)
Let's apply the same quirk as commit cbc00c13 (ACPI: save NVS memory
for Lenovo G50-45) and reuse the function it provides. Note that this
commit was already backported to 4.9.x but not 4.4.x.
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+: requires cbc00c13
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c2650d43a4