[Dell Inspiron N5425] Unable to adjust brightness after suspend

[Po-Hsu Lin]

CID: 201206-11418 Dell Inspiron N5425

With the proprietary driver:
ii fglrx-updates 2:13.125-0ubuntu0.0.1 Video driver for the AMD graphics accelerators
The brightness cannot be adjusted after suspend.

Steps:
1. Install 12.04.4 + fglrx-updates, boot to desktop
2. Suspend and wake the system up.
3. Try to adjust the brightness with the hotkey and the applet

Expected result:
* The screen backlight could be adjusted.

Actual result:
* Brightness cannot be adjusted by any means, the brightness level indicator would change with the hotkey press

Debugging Information:
ubuntu@201206-11418:~/Desktop$ lspci -nn | grep 300
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Trinity [Radeon HD 7640G] [1002:9903]
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Thames [Radeon HD 7550M/7570M/7650M] [1002:6841]

ubuntu@201206-11418:/sys/class/backlight$ l
acpi_video0@ acpi_video1@

Tried to write brightness level value into the "Brightness" file in the above directories, not working.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: fglrx-updates 2:13.125-0ubuntu0.0.1
ProcVersionSignature: Ubuntu 3.11.0-15.25~precise1-generic 3.11.10
Uname: Linux 3.11.0-15-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Fri Mar 21 06:09:27 2014
InstallationMedia: Ubuntu 12.04.4 LTS "Precise Pangolin" - Release amd64 (20140204)
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: fglrx-installer-updates
UpgradeStatus: No upgrade log present (probably fresh install)

[Po-Hsu Lin (cypressyew)]

This also affects the proprietary driver:
fglrx-experimental-13 2:13.300-0ubuntu0.0.1

For another driver, fglrx 2:13.101-0ubuntu0.0.1, brightness control does not work properly on this system.

[Po-Hsu Lin (cypressyew)]

The dim brightness test would fail after this happened.
The brightness won't be changed.

[Po-Hsu Lin (cypressyew)]

ubuntu@201206-11418:/media/Ubuntu$ dmesg | grep 'ACPI: Video'
[ 6.006527] ACPI: Video Device [VGA] (multi-head: yes rom: no post: no)
[ 6.008846] ACPI: Video Device [VGA1] (multi-head: yes rom: no post: no)

[Alberto Milone (albertomilone)]

We should involve AMD, as I believe it's an issue in the fglrx driver.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Ivan (ivanp)]

I'm using Ubuntu 14.04 with fglrx 2:13.350.1-0ubuntu2.

Debugging information:
ivan@ivanho:~$ lspci -nn | grep 300
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] BeaverCreek [Radeon HD 6620G] [1002:9641]

If I press Ctrl-F1, restart lightdm, brightness can be adjusted again.

[Ivan (ivanp)]

FYI it is fixed with the latest catalyst beta (http://support.amd.com/en-us/kb-articles/Pages/latest-linux-beta-driver.aspx).

[Michele Roviello (micheleroviello)]

I confirm, the beta fixes the issue.