Package Details: ddcci-driver-linux-dkms 0.4.2-1

Git Clone URL: (read-only, click to copy)
Package Base: ddcci-driver-linux-dkms
Description: A pair of Linux kernel drivers for DDC/CI monitors (DKMS)
Upstream URL:
Keywords: backlight hdmi monitor
Licenses: GPL2
Conflicts: ddcci-driver-linux
Submitter: irtimmer
Maintainer: surefire
Last Packager: surefire
Votes: 28
Popularity: 0.61
First Submitted: 2017-04-15 18:51 (UTC)
Last Updated: 2021-12-01 05:37 (UTC)

Latest Comments

stas commented on 2022-02-16 19:26 (UTC)

This is a great package, but can it specify the required dependencies please: dkms and linux-headers?

tukusejssirs commented on 2022-01-15 18:57 (UTC)

I tried to install this package, but the following error was shown:

 -> Could not find all required packages:
    ddci-driver-linux (Target)

Is there a missing dependency or am I missing a package?

bms commented on 2021-11-14 00:59 (UTC)

FYI: this will not compile with recent kernels due to kernel commit fc7a6209d5710618eb4f72a77cd81b8d694ecf89 (a trivial callback signature change). A merge request request is currently pending upstream which will bump the version too, but the fix is easy to apply in the meantime if needed:

uint2048_t commented on 2021-11-11 23:48 (UTC)

Just an FYI: I had to add myself to the i2c group and copy over the ddcci udev rules to get this working on startup

Andrej.Korshikov commented on 2021-08-20 04:37 (UTC)

Well, it depends on situation. There is no hang at boot now, I confirm, but ddcci_backlight still can't detect external (HDMI) monitor during sddm.service startup. So, in my use case (laptop with intel's video and external HDMI monitor) I still need systemd unit with Before=sddm.service.

SebastienWae commented on 2021-08-17 11:50 (UTC)

fyi once the package is updated to 0.4 Andrej.Korshikov workaround will no longer be needed, ddcci_backlight can be loaded from /etc/modules-load.d/ commented on 2021-04-03 08:28 (UTC)

Andrej.Korshikov you are right. So I am going to correct myself: you don't need this dkms if you want to control backlight only on one screen :-).

Andrej.Korshikov commented on 2021-04-03 06:06 (UTC) (edited on 2021-04-03 06:06 (UTC) by Andrej.Korshikov)

Hi, thanks for the info. From that reddit thread,

PowerDevil cannot deal with more than one brightness source,


while both of the monitors change their brightness value on the same scale (from 0 to 100), the effective brightness is different because the two have different backlight illumination at the same value.

For example, my brightness values usually are 65 for laptop screen and 40 for external monitor. As far as I understand I can't independently manage brightness values for different monitors without this dkms. I would be glad if I'm wrong.

And, without this dkms there is no backlight device in /sys/class/backlight for my external monitor. commented on 2021-03-30 10:38 (UTC) (edited on 2021-03-30 10:40 (UTC) by

This dkms is no more needed, because now is powerdevil compiled with


But still is needed to have i2c_dev loaded before sddm, so the systemd unit, which I am using is:


ExecStart=/usr/bin/modprobe i2c_dev
ExecStop=/usr/bin/modprobe --remove i2c_dev


More info is here: commented on 2020-09-11 12:20 (UTC)

Andrej.Korshikov thanks a lot for your comment, it really helped me.

Andrej.Korshikov commented on 2020-06-20 04:08 (UTC)


# Placing "ddcci_backlight" into /etc/modules-load.d
# leads to hang on boot with external (HDMI) monitor
# connected to the laptop, so we need to add the module later.

# And ddcci_backlight can't detect monitor during sddm.service startup.


ExecStart=/usr/bin/modprobe ddcci_backlight
ExecStop=/usr/bin/modprobe --remove ddcci_backlight


surefire commented on 2019-12-26 04:57 (UTC)

@Chrissss What if you have a linux-lts kernel?

dkms already has an optional dependency on all the kernels in the repository.

Chrissss commented on 2019-12-26 00:15 (UTC)

I think the linux-headers should be a dependecy. Without them I get the following error, when installing the PKGBUILD:

(2/3) Install DKMS modules
==> Unable to install module ddcci/0.3.3 for kernel *: Missing kernel headers.
(3/3) Removing old cached pacakges...

After running pacman -S linux-headers the module gets built and installed successfully.

mickael9 commented on 2018-01-12 22:06 (UTC)

Would you consider including my patch: (raw diff: ?