All Issues: Problem Description
---------------------------------------------------
1. Time and date of problem:

persistent

2. System architecture(s):

i386

3. Provide a clear and concise problem description as it is understood at the time of escalation. Please be as specific as possible in your description. Do not use the generic term "hang", as that can mean many things.
Observed behavior:

Customer is not able to adjust the display brightness any longer with the kernel releases 2.6.18-150 and 2.6.18-155 on Lenovo T61 laptops with the FN keys. It's still possible to increase and decrease the brightness by writing directly in the appropriate proc files.

Desired behavior:

FN keys should work like they did with older kernel releases.

4. Specific action requested of SEG:

Check if this is a regression and fix it :)

5. Is a defect (bug) in the product suspected? yes/no

yes   

Bugzilla number (if one already exists):

N/A

6. Does a proposed patch exist? yes/no

no

7. What is the impact to the customer when they experience this problem? This is especially important for severity one and two issues:

This problem occurs on a huge number of laptops and LVM is getting tough feedback from their internal "customers" since they have to work with dark displays every day. For them this is a major issue, so we need to get this sorted quickly.


All Issues: Supporting Information
------------------------------------------------------
1. Other actions already taken in working the problem (tech-list posting, google searches, fulltext search, consultation with another engineer, etc.):
  Relevant data found (if any):

2. Attach sosreport.

attached.

3. Attach other supporting data (if any).

N/A

4. Provide issue reproduction information, including location and access of reproducer machine, if available.

The display gets dark after logging into the desktop, when gnome-power-manager runs. The system does not respond to any changes in the brightness settings regardless which tool they use (gnome-power-manager e.g.)

Using the proc files is only possible if they reduce the brightness first and then increase to the max.

1. What's the last kernel dimming worked successfully with? 
  kernel-2.6.18-78.el5
2. Do the hotkeys work to adjust the brightness before you log in?
  not with the old kernel and not with the current
3. Can you please provide the necessary steps to adjust brightness via proc files? Especially the need to first reduce the brightness before you can increase it?
  - Login
  - open a root shell
  - cat /proc/acpi/ibm/brightness (level: 15)
  - echo down > /proc/acpi/ibm/brightness result is that the brightness comes up but level is now 14
  - echo up >/proc/acpi/ibm/brighness

5. Known hot-fix packages on the system:

The installed kernel package -150 is used within LVM as a hotfix for another issue. The original issue did not affect the T61 systems, but unfortunately LVM rolled out this kernel to all of their machines.

6. Customer applied changes from the last 30 days:

Installed the -150 kernel as a hotfix.



Issue escalated to Support Engineering Group by: mkarg.

Severity set to: High

SEG Notes:

I'm wondering if this is related to the fix in
https://enterprise.redhat.com/issue-tracker/?module=issues&action=view&tid=29368 is related to this