Bug 100421

Summary:	Huge delay when pressing Fn keys and (un)plugging power on a Lenovo U530 Laptop
Product:	ACPI	Reporter:	marcus.behrendt.86
Component:	EC	Assignee:	Lv Zheng (lv.zheng)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	aaron.lu, lv.zheng
Priority:	P1
Hardware:	x86-64
OS:	Linux
Kernel Version:	v4.0+	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	dmesg with first bad commit

Description marcus.behrendt.86 2015-06-24 07:06:05 UTC

Created attachment 180741 [details]
dmesg with first bad commit

I reported this bug several weeks ago, but I think in the wrong section and without much information.

https://bugzilla.kernel.org/show_bug.cgi?id=99291

The problem is that since linux 4.0 the recognition of the power supply state has a huge delay (seconds up to minutes) on a Lenovo U530 Laptop. 
cat /sys/class/power_supply/BAT1/status hangs and won't print any output after I plug or unplug the power.
Also some Fn keys are hit by this delay (Brightness and Monitor off).
This issue was not present before.

Nevertheless I bisected the issue to 

commit 74443bbed72ab22ee005ecb6ecdc657a8018e1db
Author: Lv Zheng <lv.zheng@intel.com>
Date:   Wed Jan 14 19:28:47 2015 +0800

I also tried to boot with a lot of combinations of "acpi_osi", but nothing helped. 
So linux is almost not usable for me since version 4.0.

Comment 1 Lv Zheng 2015-06-24 07:14:26 UTC

Hi,

This should be a known issue.

Please first help to confirm if this is a duplicate bug of Bug 87381:
https://bugzilla.kernel.org/show_bug.cgi?id=97381

Please try linux-pm/linux-next branch here:
# git clone git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
# git checkout linux-next

-Lv

Comment 2 Lv Zheng 2015-06-24 07:15:09 UTC

Sorry, it should be 97381 not 87381.
The patches to fix this issue are already merged by linux-pm tree.

Thanks
-Lv

Comment 3 marcus.behrendt.86 2015-06-24 08:10:49 UTC

Thanks. This seems promising. Sorry that I missed that report. I'll try and report back.

Comment 4 marcus.behrendt.86 2015-06-24 09:13:37 UTC

I can confirm linux-pm fixes the problems for me. Any guess when this will be merged into mainline?

Comment 5 Lv Zheng 2015-06-25 00:13:17 UTC

It's 4.2 material.
You may see it after a 4.2-rcx release cycle.

Aaron, can you help to assign this bug to me and close it.

Thanks and best regards
-Lv

Comment 6 Lv Zheng 2015-07-06 04:40:31 UTC

The patches can be found in linux/master branch now.
Closing the bug...

Thanks and best regards
-Lv