Brightness Adjustment

I have a dell 7710, and I just installed Korora 25 on it. This problem was also present under generic Fedora, but I prefer Cinnamon to Gnome.

The issue is that the brightness fn keys don't work. It appears as though they're changing the value in the wrong file. In my /sys/class/backlight I have a folder for amd_gpu and intel_backlight. I can see the fn keys adjusting the value in the amd_gpu/brightness file, but this does nothing. If I change the values manually in the intel_backlight/brightness file the brightness of the screen changes. Is there any way to remap this?

 

Just a thought, have you tried setting acpi_backlight=vendor on the boot command line?

 

I tried that to no avail. I also have tried to use the dconf-editor to edit "backlight-helper-force" and "backlight-helper-preference-order" but it doesn't seem to make a difference what they're set as, the brightness still doesn't change.

 

Does Korora 25 come with kernel version 4.8.x, if its lower say 4.4 I'd advise you to upgrade to 4.8 to get better support for skylake models and battery life improvements.

 

I just checked, and the live usb is on version 4.8. I'm installing again (I had switched to a different distro to test) and I will see if updating the kernel makes any difference. Brightness adjustment works on linux Mint 18.2, Antergos (Arch Linux), and Ubuntu 17.04 as well.

 

Try Ubuntu/Xubuntu LTS version 16.04.2, it comes with 4.8 kernel. Sometimes, brightness on LiveCD works and after installing the brightness doesn't work. Though, its a rare case.

 

Oddly enough, it didn't work with 17.04 when installed actually. I thought it would because it worked with mint, but it was a no go. That said, I installed the Fedora 26 beta, and it's working just fine there once it's updated to current. I really prefer fedora to ubuntu anyway, so I think I'll just stay here, at least for now. Thanks for the suggestions and the help.

 

Sorry to hear that. Now, I sound like a company representative, Haha. If you want to try Ubuntu 16, make sure the NV driver you choose must be v375 or greater.

 

Have you tried putting the line
Option "backlight" "intel_backlight"
in the xorg conf section for the intel gpu?

 

option backlight...

 

If you can confirm that your backlight driver is indeed intel_backlight, via the contents of:

ls /sys/class/backlight/


Here's how you can define the backlight driver for xorg to use:

Create a custom xorg conf file that won't be overwritten by Ubuntu's gpumanager:

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

Then edit it as shown:

sudo nano /usr/share/X11/xorg.conf.d/20-intel.conf

With the content:

Section "Device"
Identifier "card0"
Driver "intel"
Option "Backlight" "intel_backlight"
BusID "PCI:0:2:0"
EndSection

Then log in and log out again.

 

Be sure to confirm that the PCIID for your Intel HD Graphics controller matches the entry above (PCI:0:2:0).
Otherwise, change it to what your system reports.

Run this:

lspci -vnn | grep VGA -A 12

And also this:

lspci -vnn | grep 3D -A 12

The first should print details for the Integrated Intel Graphics, and the second should display details for the AMD GPU on your system.

 

@Dennismungai Do you know why HD 530 has artifacts on default driver and I had to create a conf to add SNA,Backlight,DRI 3 to get rid off artifacts. Sadly, my nvidia driver is wrecked after I installed mesa vulkan and I might have revert to earlier snapshot I did.
So my question, does Optimus/Nvidia driver support DRI3 on Xorg on Xubuntu18?

 

What kernel version are you running? Confirm with uname -r.

Remove mesa vulkan. You don't need it as your primary renderer is the NVIDIA GPU. Mesa Vulkan ICD is only for the opensource mesa driver stack.

Only enable DRI3 for the Intel driver, with a separate xorg config as shown below.

To enable DRI3, you need to create a config for the integrated card adding the DRI3 option:

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

Then edit it as shown:

sudo nano /usr/share/X11/xorg.conf.d/20-intel.conf

With the content:

Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "DRI" "3"
#Option "Backlight" "intel_backlight"
BusID "PCI:0:2:0"
EndSection

See that I've commented out the backlight section as it may not apply to your system. Only toggle it on if you're affected. See previous post.

 

A few notes concerning Vulkan:

1. Despite being an Installable Client Driver-based platform, do not assume that Vulkan ICDs will coexist nicely. To provide an example: If your primary renderer (for 3D, etc) is an NVIDIA GPU, do not install the Intel Vulkan driver.

2. Vulkan, as an ICD-based platform, has some requirements, namely:

(a). The Vulkan ICD loader. This is satisfied by:

apt install vulkan-utils vulkan

On NVIDIA based systems. If you're using an AMD GPU with the FOSS drivers, use:

apt install libvulkan1 mesa-vulkan-drivers vulkan-utils

(b). The device driver. This is satisfied by simply installing the latest NVIDIA driver.

Some caveats:

1. Ensure that DRI3 is forced on as shown in the post above for Intel if you're on switchable graphics.
2. If, for whatever reason, the Intel ANV Vulkan driver, or a similar package was installed as a dependency and you don't want to remove it as not to break the system, you can set the VK_ICD_FILENAMES variable pointing to /usr/share/vulkan/icd.d/nvidia_icd.json in /etc/environment:

sudo nano /etc/environment

Add:

export VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/nvidia_icd.json

Double check that the ICD file above is valid for NVIDIA.

The variable is taken from the Arch wiki entry on Vulkan.

 

I added the same thing along with Intel backlight because brightness was too low and there wasn't any option to set it. DRI3 is really good and snappy than DRI2.
I removed mesa-vulkan but I can't see CUDA/OpenCL ICD and driver because I'm stuck at blackscreen at boot. Even Alt-F2 for tty console is not working. Another bug I observed, out of the blue Sound/volume keys will not reduce volume at all. So I had to install Creative alsa package w/ dkms. Really odd issue which wasn't there on Ubuntu 18. Do you recommend creative alsa driver?

 

Hmm, show us the output of:

sudo dkms status

Yes. Use it.

 

Here you go:

Code:

nvidia, 396.54, 4.15.0-34-generic, x86_64: installed
oem-audio-hda-daily, 0.201808050301~ubuntu18.04.1, 4.15.0-34-generic, x86_64: installed

 

So, with that current DKMS status (which indicates that the NVIDIA driver is installed), you still experience boot to black screen?

Show me your xorg.conf. There may be multiple files in the config directory.

 

I'm stuck at cursor blinking just after seeing Xubuntu Logo.
How do you check xorg.conf file? And I don't see one. I remember nvidia complaining xorg file not found when xubuntu 18 was working fine.

 

You can still boot into recovery mode (via the grub menu).

In that mode, you can remount / as read-write (simply run fsck) and you'll be able to drop to root shell prompt and navigate the file system.

 

Already on Linux after booting into recovery and switching to Intel GPU brought my display back to life!