System and Network configuration • Brightness controls change but actual brightness does not

Hello,

Your computer is a LENOVO MIIX 300-10IBY 80NR marketed in 2015.

It uses a special form-factor (it is a tablet with a separate keyboard). So, it is not a common laptop.

For testing, I booted a live USB Fedore KDE. There, /sys/class/backlight contains a different entry, intel_backlight, and controls/slider work: The actual monitor brightness changes.

What is the Fedora kernel version and/or the Fedora version ?

The machine is several years old. Bought it in 2016 I think. Here's the output of inxi -Fa --za:

Code:

Graphics:  Device-1: Intel Atom Processor Z36xxx/Z37xxx Series Graphics & Display    vendor: Lenovo driver: i915 v: kernel arch: Gen-7 process: Intel 22nm    built: 2012-13 ports: active: DSI-1 empty: DP-1, DP-2, HDMI-A-1, HDMI-A-2    bus-ID: 00:02.0 chip-ID: 8086:0f31 class-ID: 0300  Display: wayland server: X.Org v: 1.22.1.9 with: Xwayland v: 22.1.9    compositor: kwin_wayland driver: X: loaded: modesetting unloaded: fbdev,vesa    dri: crocus gpu: i915 display-ID: :1 screens: 1  Screen-1: 0 s-res: 1280x800 s-dpi: 96 s-size: 339x212mm (13.35x8.35")    s-diag: 400mm (15.74")  Monitor-1: DSI-1 mapped: XWAYLAND0 res: 1280x800 hz: 60 dpi: 151    size: 216x135mm (8.5x5.31") modes: 800x1280  API: OpenGL v: 4.2 Mesa 22.3.6 renderer: Mesa Intel HD Graphics (BYT)    direct-render: Yes

The intel_backlight file in /sys/class/backlight is generated by the kernel:

• it may be useful to check the system journal after booting with the kernel parameter drm.debug=0x1ff (this should enable diagnostic messages in the DRM kernel code of the i915 kernel module, which should be responsible for handling display brightness)

• What is the output of the following commands ?

  Code:

  cd /sys/class/backlightls -lacd acpi_video0/ls -lacat brightnesscat max_brightnesscat actual_brightnesscat scale

• What is the current BIOS version ?

• What happens if you switch from Wayland to Xorg instead of Wayland as Desktop Manager ? Does the brightness is correctly handled ?

Hope that helps.

Statistics: Posted by Aki — 2024-09-02 17:13 — Replies 9 — Views 307

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