Same bug found after last system update: Machine: Dell Latitude 7390 BIOS: 1.41.1 (just updated) CPU: Intel Core i7-8650U GPU: Intel UHD Graphics 620 (Kabylake, device ID 5917) OS: Linux Mint 22.3 (Ubuntu 24.04 base)
Kernel 6.17.0-35-generic: WORKING - max_brightness: 7500 - Screen brightness fully functional - All brightness levels visible and usable Kernel 7.0.0-28-generic: BROKEN - max_brightness: 1023 (changed scale) - Screen extremely dark even at 100% brightness (1023/1023) - Below 50% brightness screen completely black - High contrast mode needed to see anything - Color profile loads correctly - Issue appears immediately after system boot dmesg | grep -i "i915\|backlight\|drm\|kbl" > ~/backlight-bug-report.txt [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-7.0.0-28-generic root=UUID=97b8b048-8848-4b58-89b9-72994e295c84 ro quiet splash i915.enable_psr=0 [ 0.015295] ACPI: HPET 0x0000000079FA74E0 000038 (v01 INTEL KBL-ULT 00000001 MSFT 0000005F) [ 0.015316] ACPI: LPIT 0x0000000079FA9900 000094 (v01 INTEL KBL-ULT 00000000 MSFT 0000005F) [ 0.083185] Kernel command line: BOOT_IMAGE=/vmlinuz-7.0.0-28-generic root=UUID=97b8b048-8848-4b58-89b9-72994e295c84 ro quiet splash i915.enable_psr=0 [ 0.751106] ACPI: bus type drm_connector registered [ 0.764722] simple-framebuffer simple-framebuffer.0: [drm] Registered 1 planes with drm panic [ 0.764734] [drm] Initialized simpledrm 1.0.0 for simple-framebuffer.0 on minor 0 [ 0.767025] simple-framebuffer simple-framebuffer.0: [drm] fb0: simpledrmdrmfb frame buffer device [ 14.121251] systemd[1]: Starting [email protected] - Load Kernel Module drm... [ 14.140035] systemd[1]: [email protected]: Deactivated successfully. [ 14.140241] systemd[1]: Finished [email protected] - Load Kernel Module drm. [ 15.473168] i915 0000:00:02.0: [drm] Found kabylake (device ID 5917) integrated display version 9.00 stepping C0 [ 15.514166] i915 0000:00:02.0: vgaarb: deactivate vga console [ 15.518218] i915 0000:00:02.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=io+mem [ 15.520665] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/kbl_dmc_ver1_04.bin (v1.4) [ 15.638680] mei_hdcp 0000:00:16.0-b638ab7e-94e2-4ea2-a552-d1c54b627f04: bound 0000:00:02.0 (ops i915_hdcp_ops [i915]) [ 15.807677] i915 0000:00:02.0: [drm] Registered 3 planes with drm panic [ 15.812869] [drm] Initialized i915 1.6.0 for 0000:00:02.0 on minor 1 [ 15.848066] fbcon: i915drmfb (fb0) is primary device [ 15.848081] i915 0000:00:02.0: [drm] fb0: i915drmfb frame buffer device [ 16.367777] snd_hda_intel 0000:00:1f.3: bound 0000:00:02.0 (ops intel_audio_component_bind_ops [i915]) Tried without success: - i915.enable_psr=0 - acpi_backlight=native - acpi_backlight=video - i915.enable_fbc=0 - BIOS update to 1.41.1 Currently using kernel 6.17.0-35 as workaround. System info: === Kernel === 7.0.0-28-generic === CPU/GPU === 00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (rev 07) === Backlight === max_brightness: 1023 (previuosly 7500) === BIOS === 1.41.0 === OS-release === NAME="Linux Mint" VERSION="22.3 (Zena)" ID=linuxmint ID_LIKE="ubuntu debian" VERSION_CODENAME=zena UBUNTU_CODENAME=noble -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2161148 Title: [SRU] intel_backlight (i915/eDP AUX-DPCD) stops responding to live brightness writes in 7.0.0-28-generic (works in 6.17.0-40-generic) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2161148/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
