Reading /proc/acpi/button/lid/LID0/state spews into kern.log

[Jeff Abrahamson]

Executing

$ cat /proc/acpi/button/lid/LID0/state

usually returns one line, like this:

state: open

But recently it has also started to spew quite a lot of data to kern.log. On this host and this kernel rev, I see 177 lines in the log from this one access.

I've attached a file with what appears in kern.log from one such access.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: acpi (not installed)
ProcVersionSignature: Ubuntu 3.16.0-25.33-generic 3.16.7
Uname: Linux 3.16.0-25-generic i686
ApportVersion: 2.14.7-0ubuntu8
Architecture: i386
CurrentDesktop: ratpoison
Date: Sat Nov 29 20:28:43 2014
EcryptfsInUse: Yes
InstallationDate: Installed on 2010-03-13 (1722 days ago)
InstallationMedia: Ubuntu-Netbook-Remix 9.10 "Karmic Koala" - Release i386 (20091028.4)
SourcePackage: acpi
UpgradeStatus: Upgraded to utopic on 2014-11-19 (10 days ago)

[Jeff Abrahamson (jeff-purple)]

It is just possible that this bug is related to this other bug, a possible regression in the i915 driver:
http://lists.freedesktop.org/archives/intel-gfx/2014-May/045519.html

The symptoms are similar even if the circumstances are not exactly the same. But since I'm explicitly reading the lid state, the circumstances may actually be quite close.

[Jeff Abrahamson (jeff-purple)]

I've probably mis-classified this bug in retrospect. The problem is assuredly in the acpi kernel module, not the (not installed) acpi user-space utility.