Bug#1140659: powerdevil: Lacks permissions to access I2C devices

Package: powerdevil
Version: 4:6.6.5-3
Severity: normal
X-Debbugs-Cc: [email protected]

Dear Maintainer,

There are repeated errors in journald to this effect:

org_kde_powerdevil: Exception in function i2c_all_relevant_i2c_buses_rw:
status=EACCES(-13): Permission denied
org_kde_powerdevil:  libddcutil requires RW access to all /dev/i2c devices that
might be used for DDC.
org_kde_powerdevil: Caused by:
org_kde_powerdevil:  Exception in function i2c_open_bus_basic:
status=EACCES(-13): Permission denied
org_kde_powerdevil:  Open failed for /dev/i2c-0, errno=EACCES(-13): Permission
denied in file i2c_bus_cor>

I understand from my brief research that Debian sets /dev/i2c* root ownership,
which breaks non-privileged processes trying to access it. From
https://www.kubuntuforums.net/forum/current-supported-
releases/kubuntu-26-04/692450-trying-to-solve-kde-plasma-power-management-
powerdevil-configuration-bug%E2%80%A6 , it seems that udev rules or relaxing
permissions or ownership quickly solves the issue.

However, before adding exceptions, I'm wondering whether Debian can ship with a
recommended udev file or some other workaround.


-- System Information:
Debian Release: forky/sid
  APT prefers testing
  APT policy: (501, 'testing'), (500, 'testing-debug'), (1, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 7.0.12+deb14.1-amd64 (SMP w/4 CPU threads; PREEMPT)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages powerdevil depends on:
ii  libc6                                        2.42-16
ii  libcap2-bin                                  1:2.78-1
ii  libddcutil5                                  2.2.6-1
ii  libkf6authcore6                              6.23.0-2
ii  libkf6configcore6                            6.23.0-3
ii  libkf6coreaddons6                            6.23.0-2
ii  libkf6crash6                                 6.23.0-2
ii  libkf6dbusaddons6                            6.23.0-2
ii  libkf6globalaccel6                           6.23.0-2
ii  libkf6i18n6                                  6.23.0-3
ii  libkf6idletime6                              6.23.0-2
ii  libkf6kcmutilscore6                          6.23.0-2
ii  libkf6kcmutilsquick6                         6.23.0-2
ii  libkf6runner6                                6.23.0-4
ii  libkf6screen8                                4:6.6.5-2
ii  libkf6screendpms8                            4:6.6.5-2
ii  libkf6service-bin                            6.23.1-2
ii  libkf6service6                               6.23.1-2
ii  libkf6solid6                                 6.23.0-2
ii  libkf6xmlgui6                                6.23.0-2
ii  libkirigamiplatform6                         6.23.1-3
ii  libkscreen-bin                               4:6.6.5-2
ii  libkworkspace6-6                             4:6.6.5-2
ii  libplasma7                                   6.6.5-2
ii  libpowerdevilcore2                           4:6.6.5-3
ii  libqcoro6dbus0t64                            0.13.0-2
ii  libqt6core6t64 [qt6-base-private-abi]        6.10.2+dfsg-15
ii  libqt6dbus6                                  6.10.2+dfsg-15
ii  libqt6gui6                                   6.10.2+dfsg-15
ii  libqt6qml6 [qt6-declarative-private-abi]     6.10.2+dfsg-6
ii  libqt6quick6                                 6.10.2+dfsg-6
ii  libstdc++6                                   16.1.0-1
ii  plasma-desktoptheme                          6.6.5-2
ii  plasma-version [plasma-version-base-6.6]     6.6.1
ii  powerdevil-data                              4:6.6.5-3
ii  qml6-module-org-kde-config                   6.23.0-3
ii  qml6-module-org-kde-coreaddons               6.23.0-2
ii  qml6-module-org-kde-kcmutils                 6.23.0-2
ii  qml6-module-org-kde-kirigami                 6.23.1-3
ii  qml6-module-org-kde-kirigamiaddons-formcard  1.12.0-1
ii  qml6-module-org-kde-kitemmodels              6.23.0-2
ii  qml6-module-org-kde-ksvg                     6.23.0-2
ii  qml6-module-org-kde-kwindowsystem            6.23.0-2+b1
ii  qml6-module-org-kde-notifications            6.23.0-2
ii  qml6-module-org-kde-plasma-workspace         4:6.6.5-2
ii  qml6-module-qtcore                           6.10.2+dfsg-6
ii  qml6-module-qtquick                          6.10.2+dfsg-6
ii  qml6-module-qtquick-controls                 6.10.2+dfsg-6
ii  qml6-module-qtquick-dialogs                  6.10.2+dfsg-6
ii  qml6-module-qtquick-layouts                  6.10.2+dfsg-6

Versions of packages powerdevil recommends:
ii  power-profiles-daemon  0.30-2
ii  systemsettings         4:6.6.5-2

powerdevil suggests no packages.

-- no debconf information