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teturtle

Member

Registered: 2025-07-20

Posts: 2

Trouble installing ddcci-driver-linux-dkms.

I am trying to setup monitor brightness using brightnessctl with an external monitor. I am following this wiki section trying to use ddcci-driver-linux-dkms.

I have installed ddcci-driver-linux-dkms 0.4.5-1 with

yay -S ddcci-driver-linux-dkms

and rebooted afterwards. I have tried

sudo modprobe ddcci

which returned

modprobe: FATAL: Module ddcci not found in directory /lib/modules/6.15.7-arch1-1

and

sudo modprobe ddcci_backlight

which returned

modprobe: FATAL: Module ddcci_backlight not found in directory /lib/modules/6.15.7-arch1-1

I use the Nvidia proprietary drivers and have linux headers installed.

Running

lsmod | grep "ddcci"

tree /lib/modules/6.15.7-arch1-1 | grep "ddcci"

tree /usr/lib/modules/6.15.7-arch1-1 | grep "ddcci"

ls -A /sys/class/backlight

all return nothing leading me to believe the module is unavailable. After more searching, I noticed this in the yay log

==> dkms install --no-depmod ddcci/0.4.5 -k 6.15.7-arch1-1
Deprecated feature: CLEAN (/usr/src/ddcci-0.4.5/dkms.conf)

Error! Bad return status for module build on kernel: 6.15.7-arch1-1 (x86_64)
Consult /var/lib/dkms/ddcci/0.4.5/build/make.log for more information.

/var/lib/dkms/ddcci/0.4.5/build/make.log contains:

DKMS (dkms-3.2.1) make.log for ddcci/0.4.5 for kernel 6.15.7-arch1-1 (x86_64)
Sun Jul 20 04:29:08 PM EDT 2025

Building module(s)
# command: make -j20 KERNELRELEASE=6.15.7-arch1-1 KVER=6.15.7-arch1-1 -C /var/lib/dkms/ddcci/0.4.5/build
make: Entering directory '/var/lib/dkms/ddcci/0.4.5/build'
make -C "ddcci"
make[1]: Entering directory '/var/lib/dkms/ddcci/0.4.5/build/ddcci'
make -C "/lib/modules/6.15.7-arch1-1/build" M="/var/lib/dkms/ddcci/0.4.5/build/ddcci" modules
make[2]: Entering directory '/usr/lib/modules/6.15.7-arch1-1/build'
make[3]: Entering directory '/var/lib/dkms/ddcci/0.4.5/build/ddcci'
  CC [M]  ddcci.o
ddcci.c:1296:27: error: initialization of ‘int (*)(struct device *, const struct device_driver *)’ from incompatible pointer type ‘int (*)(struct device *, struct device_driver *)’ [-Wincompatible-pointer-types]
 1296 |         .match          = ddcci_device_match,
      |                           ^~~~~~~~~~~~~~~~~~
ddcci.c:1296:27: note: (near initialization for ‘ddcci_bus_type.match’)
ddcci.c:1231:12: note: ‘ddcci_device_match’ declared here
 1231 | static int ddcci_device_match(struct device *dev, struct device_driver *drv)
      |            ^~~~~~~~~~~~~~~~~~
ddcci.c:1827:27: error: ‘I2C_CLASS_SPD’ undeclared here (not in a function); did you mean ‘I2C_CLASS_HWMON’?
 1827 |         .class          = I2C_CLASS_SPD,
      |                           ^~~~~~~~~~~~~
      |                           I2C_CLASS_HWMON
make[5]: *** [/usr/lib/modules/6.15.7-arch1-1/build/scripts/Makefile.build:203: ddcci.o] Error 1
make[4]: *** [/usr/lib/modules/6.15.7-arch1-1/build/Makefile:2003: .] Error 2
make[3]: *** [/usr/lib/modules/6.15.7-arch1-1/build/Makefile:248: __sub-make] Error 2
make[3]: Leaving directory '/var/lib/dkms/ddcci/0.4.5/build/ddcci'
make[2]: *** [Makefile:248: __sub-make] Error 2
make[2]: Leaving directory '/usr/lib/modules/6.15.7-arch1-1/build'
make[1]: *** [Makefile:38: ddcci.ko] Error 2
make[1]: Leaving directory '/var/lib/dkms/ddcci/0.4.5/build/ddcci'
make: *** [Makefile:28: ddcci] Error 2
make: Leaving directory '/var/lib/dkms/ddcci/0.4.5/build'

# exit code: 2
# elapsed time: 00:00:02
----------------------------------------------------------------

Full yay log:

AUR Explicit (1): ddcci-driver-linux-dkms-0.4.5-1
:: PKGBUILD up to date, skipping download: ddcci-driver-linux-dkms
  1 ddcci-driver-linux-dkms                  (Installed) (Build Files Exist)
==> Packages to cleanBuild?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)
==>   1 ddcci-driver-linux-dkms                  (Installed) (Build Files Exist)
==> Diffs to show?
==> [N]one [A]ll [Ab]ort [I]nstalled [No]tInstalled or (1 2 3, 1-3, ^4)
==> ==> Making package: ddcci-driver-linux-dkms 0.4.5-1 (Sun 20 Jul 2025 04:41:11 PM EDT)
==> Retrieving sources...
  -> Found ddcci-driver-linux-v0.4.5.tar.gz
==> Validating source files with b2sums...
:: (1/1) Parsing SRCINFO: ddcci-driver-linux-dkms
==> Making package: ddcci-driver-linux-dkms 0.4.5-1 (Sun 20 Jul 2025 04:41:16 PM EDT)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
  -> Found ddcci-driver-linux-v0.4.5.tar.gz
==> Validating source files with b2sums...
==> Removing existing $srcdir/ directory...
==> Extracting sources...
  -> Extracting ddcci-driver-linux-v0.4.5.tar.gz with bsdtar
==> Sources are ready.
==> Making package: ddcci-driver-linux-dkms 0.4.5-1 (Sun 20 Jul 2025 04:41:27 PM EDT)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Entering fakeroot environment...
==> Starting package()...
==> Tidying install...
  -> Removing libtool files...
  -> Purging unwanted files...
  -> Removing static library files...
  -> Stripping unneeded symbols from binaries and libraries...
  -> Compressing man and info pages...
==> Checking for packaging issues...
==> Creating package "ddcci-driver-linux-dkms"...
  -> Generating .PKGINFO file...
  -> Generating .BUILDINFO file...
  -> Generating .MTREE file...
  -> Compressing package...
==> Leaving fakeroot environment.
==> Finished making: ddcci-driver-linux-dkms 0.4.5-1 (Sun 20 Jul 2025 04:41:33 PM EDT)
==> Cleaning up...
loading packages...
resolving dependencies...
looking for conflicting packages...

Packages (1) ddcci-driver-linux-dkms-0.4.5-1

Total Installed Size:  0.09 MiB
Net Upgrade Size:      0.00 MiB

checking keyring...
checking package integrity...
loading package files...
checking for file conflicts...
checking available disk space...
:: Running pre-transaction hooks...
(1/1) Remove upgraded DKMS modules
==> dkms remove ddcci/0.4.5
:: Processing package changes...
reinstalling ddcci-driver-linux-dkms...
:: Running post-transaction hooks...
(1/3) Arming ConditionNeedsUpdate...
(2/3) Install DKMS modules
==> dkms install --no-depmod ddcci/0.4.5 -k 6.15.7-arch1-1
Deprecated feature: CLEAN (/usr/src/ddcci-0.4.5/dkms.conf)

Error! Bad return status for module build on kernel: 6.15.7-arch1-1 (x86_64)
Consult /var/lib/dkms/ddcci/0.4.5/build/make.log for more information.
==> WARNING: `dkms install --no-depmod ddcci/0.4.5 -k 6.15.7-arch1-1' exited 10
(3/3) Updating linux initcpios...
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'default'
==> Using default configuration file: '/etc/mkinitcpio.conf'
  -> -k /boot/vmlinuz-linux -g /boot/initramfs-linux.img
==> Starting build: '6.15.7-arch1-1'
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [autodetect]
  -> Running build hook: [microcode]
  -> Running build hook: [modconf]
  -> Running build hook: [kms]
  -> Running build hook: [keyboard]
  -> Running build hook: [keymap]
  -> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
  -> Running build hook: [block]
  -> Running build hook: [filesystems]
  -> Running build hook: [resume]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating zstd-compressed initcpio image: '/boot/initramfs-linux.img'
  -> Early uncompressed CPIO image generation successful
==> Initcpio image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'fallback'
==> Using default configuration file: '/etc/mkinitcpio.conf'
  -> -k /boot/vmlinuz-linux -g /boot/initramfs-linux-fallback.img -S autodetect
==> Starting build: '6.15.7-arch1-1'
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [microcode]
  -> Running build hook: [modconf]
  -> Running build hook: [kms]
==> WARNING: Possibly missing firmware for module: 'ast'
  -> Running build hook: [keyboard]
==> WARNING: Possibly missing firmware for module: 'xhci_pci_renesas'
  -> Running build hook: [keymap]
  -> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
  -> Running build hook: [block]
==> WARNING: Possibly missing firmware for module: 'qed'
==> WARNING: Possibly missing firmware for module: 'aic94xx'
==> WARNING: Possibly missing firmware for module: 'bfa'
==> WARNING: Possibly missing firmware for module: 'qla2xxx'
==> WARNING: Possibly missing firmware for module: 'qla1280'
==> WARNING: Possibly missing firmware for module: 'wd719x'
  -> Running build hook: [filesystems]
  -> Running build hook: [resume]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating zstd-compressed initcpio image: '/boot/initramfs-linux-fallback.img'
  -> Early uncompressed CPIO image generation successful
==> Initcpio image generation successful

Scimmia

Fellow

Registered: 2012-09-01

Posts: 13,694

Re: Trouble installing ddcci-driver-linux-dkms.

https://gitlab.com/ddcci-driver-linux/d … 5aebfe8116
This was fixed after the latest release.

teturtle

Member

Registered: 2025-07-20

Posts: 2

Re: Trouble installing ddcci-driver-linux-dkms.

The -git package installed successfully. I setup the nvidia kernel module parameter and setup ddcci to load during boot but ls -A /sys/class/backlight still returns nothing and brightnessctl doesn't list any new devices. ls -A /sys/bus/ddcci/devices also returns nothing so I don't think it is detecting the monitor. lsmod | grep ddcci lists ddcci and ddcci_backlight now so it is definitely loaded.