Bug 748210

Summary: Kernel panic when turning off screen backlight using laptop Fn key
Product: [Fedora] Fedora Reporter: rh
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED CURRENTRELEASE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 16CC: awilliam, bjoern, conalmccrudden, cunio, gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, next.little.owl, yangjeep
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-11-29 08:24:40 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 713566    
Attachments:
Description Flags
The kernel oops - the first screen.
none
The kernel oops - the second screen. none

Description rh 2011-10-23 01:52:51 UTC
Description of problem:
Since I installed Fedora 16 I'm not able to turn off the screen backlight using the Fn key. It is a Lenovo Ideapad Y450-PEI. When I press Fn + F2 (key to toggle screen backlight), my screen is black and I'm not able to get it back. I managed to get a strong light and see things like stack trace on my screen and something like "Kernel is unable to handle ......"

Version-Release number of selected component (if applicable):
kernel-3.1.0-0.rc10.git0.1.fc16.x86_64

How reproducible:
Every time

Steps to Reproduce:
1. Press Fn + F2 to turn off screen backlight
2. Press Fn + F2 again to turn it on
3.
  
Actual results:
The screen backlight isn't on and something is printed on the screen.

Expected results:
The screen backlight is on and nothing is affected

Additional info:
If possible, please don't let me try to read the screen when error occurs. It's so hard to do so...

Comment 1 rh 2011-10-23 01:58:54 UTC
I'm using the nouveau driver with a nVIDIA GT130M card. Haven't tried if proprietary driver will solve the problem.

Comment 2 Josh Boyer 2011-10-24 15:27:32 UTC
Can you take a picture of the screen?  We need the backtrace to really get started here.

Comment 3 rh 2011-10-25 10:42:06 UTC
(In reply to comment #2)
> Can you take a picture of the screen?  We need the backtrace to really get
> started here.

I'm sorry, when I press Fn + F2 the screen backlight turns off immediately so I can't see anything unless I use a torch... and it seems that the length of the backtrace exceeded the height of the screen...

I'll try my best to put them down. I'll reply later here.

Comment 4 Václav Mocek 2011-10-26 23:09:32 UTC
The same problem with Lenovo Ideapad S205 when I switch off/on backlight. The result is kernel oops and nothing in /var/log/messages, the version of kernel is 3.1.0-1.fc16.x86_64. 

I suspect, that the culprit is the ideapad-laptop module, see the attached pictures of the screen.

Comment 5 Václav Mocek 2011-10-26 23:10:59 UTC
Created attachment 530403 [details]
The kernel oops - the first screen.

Comment 6 Václav Mocek 2011-10-26 23:11:39 UTC
Created attachment 530405 [details]
The kernel oops - the second screen.

Comment 7 Václav Mocek 2011-10-26 23:24:11 UTC
My HW profile:
http://www.smolts.org/client/show/pub_7c1cd1be-666f-4cdb-a5da-1ef1cae21c35

Comment 8 rh 2011-10-27 14:06:43 UTC
(In reply to comment #6)
> Created attachment 530405 [details]
> The kernel oops - the second screen.

Oh thank you very much for these pictures. My screen turns off after Fn + F2 so I can't see anything.

Using Fn to toggle screen backlight is working very well in my Archlinux with the latest kernel, installed on the same machine.

Comment 9 Björn Ruberg 2011-11-02 10:16:29 UTC
I have read somewhere that the problem does not occur on ubuntu 32-bit. It does however on Ubuntu 64-bit, I confirm. So - has anybody tried this with a 32-bit Fedora installation?

Comment 10 rh 2011-11-02 12:03:20 UTC
I've updated my Archlinux to the latest kernel 3.1.0-2 and the problem can now be reproduced on Arch.

Comment 11 Václav Mocek 2011-11-02 21:31:32 UTC
It is an upstream problem and the patch is available.

https://lkml.org/lkml/2011/10/19/485

http://www.mail-archive.com/platform-driver-x86@vger.kernel.org/msg02343.html

Comment 12 Adam Williamson 2011-11-02 22:34:01 UTC
Proposing as NTH for F16: system crasher, will be present in live images hence can't be entirely fixed with an update.



-- 
Fedora Bugzappers volunteer triage team
https://fedoraproject.org/wiki/BugZappers

Comment 13 Josh Boyer 2011-11-03 13:45:42 UTC
This when upstream in 3.2 as commit d4afc7754a60b885b63ef23fd194984e2d53a4e6.  I'll bring it back to f16.

Comment 14 Josh Boyer 2011-11-03 13:53:03 UTC
The patch was added.  It will be in the next kernel build.

Comment 15 Josh Boyer 2011-11-07 20:00:29 UTC
*** Bug 746016 has been marked as a duplicate of this bug. ***

Comment 16 Jacek Pawlyta 2011-11-10 09:41:48 UTC
*** Bug 745568 has been marked as a duplicate of this bug. ***