Can't adjust backlight in openSUSE 13.1 on eMachines e525

English Install/Boot/Login
1

Hello,

I’ve installed openSUSE 13.1 (32-bit) on my eMachines e525 last week.

Unfortunately, the backlight cannot be adjusted.

I had the same problem on Ubuntu 12.04 and Linux Mint 14–16, and was able to solve the problem by running

gksudo gedit /etc/default/grub

finding the line

GRUB_CMDLINE_LINUX=""

changing it to

GRUB_CMDLINE_LINUX="acpi_osi=Linux"

and then running

sudo update-grub

as described here: http://ubuntuforums.org/showthread.php?t=1900024&p=11567591#post11567591

I edited the same file in openSUSE and updated the grub.

However, the backlight is still not adjustable. Is there anything I can do?

Many thanks for your help!

PS the related issue of the backlight not turning on, as described in the Ubuntu forums post cited above, is solved in openSUSE 13.1, as well as Mint 15/16 and Mageia 3.

2

What command did you use to update Grub2? You should update Grub2 with one of:

 grub-mkconfig -o /boot/grub/grub.cfg

OR
If your PC is UEFI-GPT Mode, this instead:

 grub-mkconfig -o /boot/efi/EFI/GRUB/grub.cfg

This will properly create an updated grub.cfg.

You need to do this from Terminal - Super User Mode

3

Thanks, Gerry!

Yes, I used

grub-mkconfig -o /boot/grub/grub.cfg

after finding that update-grub didn’t work in openSUSE.

However, I’m still unable to change the screen brightness.

4

Okay. You showed the other command, so I wasn’t sure. So, the suggested fix doesn’t work, it seems.

I do not know the solution to your problem, but I do not see anyone else jumping in here, yet.

So, I will suggest that you try the Recover mode to see what happens.

When you boot and see the Grub boot menu, go to the line for Advanced

In the next menu that pops up, choose the Recovery option.

What happens then? Anything different?

5

Looking back at the posts, I believe I have given you the wrong commands. openSUSE 13.1 uses Grub2, so you should be using the command:


grub2-mkconfig -o /boot/grub2/grub.cfg

NOT


grub-mkconfig -o /boot/grub/grub.cfg

Note the numeral 2 in the line.

When booting, you can verify whether or not your changes actually made it to the command line.

As soon as you see the first Grub menu, press the “e” key. You should see the command line with its parameters, and acpi_osi=Linux should be in there, no quotes.

I suspect if you do that right now before trying to recreate it with the grub2-mkconfig line, you will see the parameter never did make it there.

If not, you can test it before making the change permanent. While still in the edit mode for the boot command line, go to the end of the line, add a space, then add the parameter as I bolded above (no quotes, remember).

Then, boot. It will boot this way once, then it will be gone again for next boot, so if it doesn’t work, it won’t be permanent.

If it does work, then use the grub2-mkconfig command to make it permanent.

 =====

I’m surprised that wolfi nor my friend robin_listas – nor others here – didn’t spot my mistake!

6

You might want to have a look at this: https://wiki.ubuntu.com/Kernel/Debugging/Backlight#Diagnostic_Techniques

7

Thanks!

In fact, my error, I’m pretty sure I ran the command as

grub2-mkconfig -o /boot/grub2/grub.cfg

already.

Before I try anything more, I should point out that I’m in a dual-boot setup with Linux Mint 16, and I’m still getting the Mint grub at boot, even after updating the openSUSE grub. (That surprised me a bit).

Further details: I installed Mint first, then openSUSE, but before trying to solve this current problem I had re-installed the Mint grub by running

sudo grub-install /dev/sda

and then

sudo update-grub

in the Mint side.

Will this affect things? I’m surprised the openSUSE grub hasn’t returned. Everything else appeared to work normally in Terminal when I updated grub, and it even detected Mint on the other partition.

If I press the ‘e’ key upon seeing the grub, will it just give the the details for booting Mint? I have applied the same fix in my Mint install, and it works fine there.

Thanks for your help :slight_smile:

8

Which Grub is control will depend on how you install things.

Is this a UEFI machine or BIOS.If BIOS then it will depend on what is installed to the MBR. It may be generic code if so then the boot flag controls what gets booted if You did not install grub to MBR when you installed openSUSE then you probably have Mint code in the MBR.

In UEFI it depends on what is set in the EFI configuration.

9

Yeah this is a problem with eMachines laptops I have seen on various other linux distros.
Especially in the later models under the gateway brand (seriously Gateway+linux=bad juju)

10

It’s a BIOS machine.

11

Hi, zam:

The Mint dual-boot makes a minor difference, but we should still be able to fix it.

If I press the ‘e’ key upon seeing the grub, will it just give the the details for booting Mint? I have applied the same fix in my Mint install, and it works fine there

First, I am guessing that you are still able to boot to openSUSE from there (correct me if I am wrong), in which case there is an entry for it in the Grub menu.

We need to know what the command line for that entry is. If you highlight that entry, then press the “e” key, you should be able to view and edit that line. Before editing it, I would like to know what it is now.

I also would like to know if you are you running one drive or two? That is, are you dual-booting from a shared disk, or from different disks.

Give the output of

fdisk -l

Then let us take an approach from there.

12

Thanks so much for your help with this, Gerry. Here is the output from sudo fdisk -l (in the Mint side—I assume it is the same).

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0004e172

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048    58593844    29295898+  83  Linux
/dev/sda2   *    58595326   488396799   214900737    5  Extended
/dev/sda5        58595328   324927487   133166080   83  Linux
/dev/sda6       478633984   488396799     4881408   82  Linux swap / Solaris
/dev/sda7       324929536   366876671    20973568   83  Linux
/dev/sda8       366878720   478623743    55872512   83  Linux

I have openSUSE installed on sda7 and sda8. Mint is installed on sda1 and sda5, and sda6 (swap) is shared between the two systems. I have only one hard drive.

I pressed the ‘e’ key after selecting openSUSE from the boot menu. It gave me a long output, from which I quote the opening (there was no way to copy and paste it, but I can type out the whole thing if it is useful):


setparams 'openSUSE 13.1 (i586)'insmod part_msdos
insmod ext2
set root='hdo, msdos7'
if  x$feature_platform_search_hint = xy ]; then

etc. I hope this makes sense. Once again, thank-you for your help. I really appreciate the welcome and support of the openSUSE community as a new user :slight_smile:

Zam

13

First, a “just-in-case”: I have read that on some of the Acer products with this problem, for some reason the function keys for the backlight are reversed, dimming increases and increasing dims :X. Check that.

=====

I have been hoping some of the more*** well-seasoned Linux veterans*** – such as gogalthorp and others – would step in here, as I believe there are probably better methods than the approach I am going to take. But, since that is not happening so far, I will suggest trying what I would be doing right now if it was my machine and I was trying to solve the puzzle.

So far, I have found that slight differences seem to work for other people, possibly depending on differing hardware.

I would like to test – and know that I am testing – each of the following one at a time until (hopefully) one of them works:


acpi_osi=Linux

acpi_osi=!Linux

acpi_osi=Linux acpi_backlight=vendor

acpi_osi=!Linux acpi_backlight=vendor

To do that, I am going to suggest a change to your boot scheme through Grub.

I suggest you make sure you have a good recent backup of the entire drive before proceeding.

Once you have that backup:

Boot into openSUSE as regular user, not root.

Launch System => Terminal => Terminal - Super User Mode

Enter your root password at the prompt.

Just to make sure Grub is configured correctly, do:


grub2-mkconfig -o /boot/grub2/grub.cfg

Next, install the openSUSE version of Grub to the MBR. Do:


grub2-install /dev/sda

Shut down, boot, and let me know what happens next.

Good luck,

14

Yes that should install the opeSUSE grub2 code

You can only have one OS at a time control the boot you could modify Mint’s Grub or install openSUSE’s grub and modify that grub in either case most likely the kernel parameters must be changed to deal with the odd hardware.

15

On 2014-02-21 04:36, gogalthorp wrote:
>
> Yes that should install the opeSUSE grub2 code
>
> You can only have one OS at a time control the boot you could modify
> Mint’s Grub or install openSUSE’s grub and modify that grub in either
> case most likely the kernel parameters must be changed to deal with the
> odd hardware.

Right.

Only one grub, or whatever, can be installed on the MBR. The other one
has to be installed somewhere else, meaning the root or boot partition
of the other systems.

Having both wanting to use the MBR is a source of conflicts and problems.

–
Cheers / Saludos,

Carlos E. R.

(from 13.1 x86_64 “Bottle” (Minas Tirith))