Bug 1126161

Summary: Backlight brightness issue with Toshiba Portege R830 after resume
Product: [Fedora] Fedora Reporter: Sylvain Pasche <sylvain.pasche>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 21CC: extras-qa, gansalmon, hdegoede, itamar, jonathan, kernel-maint, madhu.chinakonda, mchehab
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: 1126159 Environment:
Last Closed: 2014-08-04 18:12:00 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description Flags
dmesg.log
none
dmi.log none

Description Sylvain Pasche 2014-08-02 21:52:22 UTC 
Created attachment 923522 [details]
dmesg.log

+++ This bug was initially created as a clone of Bug #1126159 +++

I reported bug 1126159 for Fedora 20. 
I gave a try with Fedora 21, the behavior is different:

By default the brightness control works well after the first boot. However, after a suspend/resume, changing the brightness has no effect and the actual brightness stays at 100%.

With the default kernel parameters
  ls /sys/class/backlight/
  acpi_video0  intel_backlight  toshiba

With the video.use_native_backlight=1 parameter
  The behavior doesn't change. Same issue as above.

  ls /sys/class/backlight/
  acpi_video0  intel_backlight  toshiba

With the acpi_backlight=vendor parameter:
  With this parameter the brightness stays at 100% after the first boot, it behaves like after a resume for the cases above.

  ls /sys/class/backlight/
  intel_backlight  toshiba
Comment 1 Sylvain Pasche 2014-08-02 21:52:53 UTC 
Created attachment 923523 [details]
dmi.log
Comment 2 Hans de Goede 2014-08-04 18:12:00 UTC 
Hi,

Thanks for also testing with F-21, and for letting us know that things behave slightly different with F-21, however  I think it is more productive to track this in a single bug (as it is likely a kernel issue, and F-20 will eventually get the new kernel from F-21 too).

So I'm going to mark this as a duplicate of your earlier bug, and then get back to you in the earlier bug.

Regards,

Hans

*** This bug has been marked as a duplicate of bug 1126159 ***