Public bug reported:
---
Summary:
---
Integrated camera (Chicony 04f2:b87a) produces only black frames on
linux-oem-26.04 kernel (7.0.0-1013-oem); works correctly on
linux-generic-hwe-26.04 (7.0.0-31-generic) with identical hardware
---
Hardware:
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Lenovo ThinkPad X1 Gen 14 (Panther Lake), integrated camera Chicony Electronics
04f2:b87a (USB, uvcvideo driver), paired IR camera 04f2 "Integrated I" also
present
---
Ubuntu version:
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lsb_release -rd
Description: Ubuntu 26.04.1 LTS
Release: 26.04
apt-cache policy linux-oem-26.04
linux-oem-26.04:
Installed: 7.0.0-1013.13
Candidate: 7.0.0-1013.13
Version table:
*** 7.0.0-1013.13 500
500 http://archive.ubuntu.com/ubuntu resolute-updates/main amd64
Packages
500 http://security.ubuntu.com/ubuntu resolute-security/main amd64
Packages
100 /var/lib/dpkg/status
---
Description:
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After a fresh install of Kubuntu 26.04 LTS (replacing a working Ubuntu 24.04
LTS install on the same hardware), the integrated color camera stopped
producing usable video. The camera enumerates correctly, the driver loads
without errors, and all UVC controls (exposure, gain, white balance) report
sane values — but every captured frame, in every application and every pixel
format (MJPG and YUYV), is solid black. No kernel errors appear in dmesg during
capture.
---
Steps to reproduce (on 7.0.0-1013-oem):
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v4l2-ctl -d /dev/video0 --set-fmt-video=width=1280,height=720,pixelformat=MJPG
--stream-mmap --stream-count=1 --stream-to=/tmp/test.jpg
Resulting image is solid black, both with auto and manual exposure.
---
What was ruled out:
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- Physical privacy shutter: confirmed open
- Exposure/gain/auto-exposure settings: default and manual values both tested,
all black
- Kernel-level errors: none in dmesg during capture, clean UVC 1.50 enumeration
- Wrong camera node: confirmed testing the "Integrated C" (color) node
specifically, not the "Integrated I" (IR) node
- USBIO bridge module (linux-modules-usbio-oem-26.04): installed and loaded,
but binds to an unrelated Synaptics device (06cb:019f), not the camera
- BIOS/firmware camera disable: no dedicated toggle found on this model beyond
the physical shutter
---
Key finding — kernel flavor comparison on identical hardware:
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A colleague with the exact same laptop model (same employer hardware rollout,
same purchase date) is running linux-generic-hwe-26.04 (kernel
7.0.0-30-generic) rather than the -oem flavor, and confirms full working camera
and graphics. I subsequently booted 7.0.0-31-generic (already installed
alongside the oem kernel on my machine) and confirmed:
- Graphics/GPU (Panther Lake) work correctly — Firefox renders smoothly, no
regression
- Camera produces correct, non-black images in the same v4l2-ctl test
- Camera and graphics both confirmed working end-to-end in Zoom (browser and
desktop app)
This isolates the bug specifically to the linux-oem-26.04 (7.0.0-1013)
kernel branch, not to Kubuntu 26.04 generally, and not to any camera
hardware fault.
---
USB extension unit descriptor (relevant to camera init):
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guidExtensionCode {26b8105a-0713-4870-979d-da79444bb68e} (Realtek Extended
Controls Unit)
bNumControls: 8, bNrInPins: 1, baSourceID: 4, bControlSize: 4, bmControls: 0x04
and a second instance:
guidExtensionCode {26b8105a-0713-4870-979d-da79444bb68e}
bNumControls: 4, bNrInPins: 1, baSourceID: 10, bControlSize: 4, bmControls: 0x00
This matches a known Chicony/Realtek camera-bridge reference design used
across multiple Lenovo generations, which in other contexts (e.g. IR
emitter enablement) has required a vendor-specific extension-unit
initialization command not implemented in the default driver path. This
suggests the -oem kernel branch may be missing an equivalent vendor
quirk/init sequence for this specific camera revision that the generic-
hwe-26.04 branch's driver/config handles correctly (or avoids
triggering).
---
Workaround:
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Booting linux-generic-hwe-26.04 instead of the -oem kernel resolves the issue
with no observed downsides on this hardware so far.
---
Remark:
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The diagnosis and this bug report was done with great help from good old Claude.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-oem-26.04 7.0.0-1013.13
ProcVersionSignature: Ubuntu 7.0.0-31.31-generic 7.0.14
Uname: Linux 7.0.0-31-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: KDE
Date: Wed Sep 9 14:31:05 2026
InstallationDate: Installed on 2026-09-05 (4 days ago)
InstallationMedia: Kubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423)
SourcePackage: linux-meta-oem-7.0
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: linux-meta-oem-7.0 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2166884
Title:
black frames from integrated camera
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