apport information
** Description changed:
Thanks in advance for taking a look. I've revised this description after
some follow-up testing; I think my original framing pointed at the wrong
thing.
What I'm seeing:
The webcam on my ThinkPad X1 Nano (Gen 2, OV2740 behind IPU6) currently
does not produce frames on either 7.0.0-14 or 7.0.0-15. libcamera and
pipewire both see an `ov2740` device, `/dev/video*` are populated, and
the IPU6 driver seems happy:
intel-ipu6 0000:00:05.0: Found supported sensor INT3474:01
intel-ipu6 0000:00:05.0: Connected 1 cameras
But every app that opens the camera fails identically:
spa.v4l2: /dev/video0: VIDIOC_S_PARM: Inappropriate ioctl for device
spa.v4l2: '/dev/video0' VIDIOC_STREAMON: Link has been severed
pw.node: (v4l2_input.pci-0000_00_05.0-110) suspended -> error (Start
error: Link has been severed)
Cheese, Snapshot, Firefox, Chromium and Zoom all behave the same way.
BIOS privacy is ok and the physical toggle has been checked.
The kernel-side warnings line up with what I'd expect if the VSC chain
never comes up:
int3472-discrete INT3472:05: cannot find GPIO chip INTC1096:00, deferring
int3472-discrete INT3472:06: cannot find GPIO chip INTC1096:00, deferring
ov2740 i2c-INT3474:01: supply AVDD not found, using dummy regulator
ov2740 i2c-INT3474:01: supply DOVDD not found, using dummy regulator
ov2740 i2c-INT3474:01: supply DVDD not found, using dummy regulator
`mei_vsc_hw` is loaded but unbound. `mei_vsc`, `intel_vsc`, `ivsc_csi`,
`ivsc_ace` aren't loaded at all. The `INT3472:05/06` deferrals are the
chain that powers the OV2740 rails, which is presumably why ov2740 ends
up on dummy regulators.
What I now believe could be a more interesting (frustrating?) bug than a
kernel-version regression:
* The camera **was** working on my stock 26.04 install on 2026-04-23.
* That install pulled in `linux-image-generic-hwe-26.04 → 7.0.0-14.14`. The
same `.14` deb is still installed today.
* `linux-firmware` is still at `20260319.git217ca6e4`, libcamera at 0.7.0-1,
pipewire/wireplumber at 1.6.2-1 / 0.5.13-1 — none have been upgraded since
install (per `/var/log/apt/history.log` and `/var/log/dpkg.log`).
* BIOS is unchanged (N3IET53W 1.33, 2025-12-03), `fwupdmgr get-history` is
empty, `/etc/modprobe.d/` has nothing camera-relevant, kernel cmdline is stock
(`ro quiet splash crashkernel=…`).
So as best I can tell, the same kernel/firmware/userspace binaries that
worked on day one are now failing, without an apt-tracked change between
those two states. The HWE bump from .14 to .15 in my original report was
just the moment I noticed.
My best guess (and I'd love to be told if it's silly) is that this is a
non-deterministic probe ordering issue around the USB-LJCA bridge — the
INTC1096 ACPI companion is present at `\_SB_.PC00.XHCI.RHUB.HS08.VGPO` but its
GPIO chip never gets registered, so int3472 can't find it, so the rails never
come up, so VSC never starts, so streamon severs the link. I don't knw why this
would sometimes succeed and sometimes not on otherwise
identical software.
ACPI layout summary (full data in attached diagnostics):
\_SB_.PC00.SPI1.SPFD HID INTC1094 (mei_vsc_hw match)
\_SB_.PC00.SPI1.SPFD.CVFD HID INTC1095
\_SB_.PC00.XHCI.RHUB.HS08.VGPO HID INTC1096 (GPIO chip never
registers)
\_SB_.PC00.XHCI.RHUB.HS08.VIC0/1 HID INTC1097
\_SB_.PC00.XHCI.RHUB.HS08.VSPI HID INTC1098
Side notes in case relevant:
* The PCH SPI controller (PCI 0000:00:1f.5, spi0) has one child for the BIOS
flash; spi-nor fails JEDEC ID on it. I think this is unrelated.
* The Intel USB-LJCA bridge (8086:0b63) at HS08 / INTC1098 brings up spi1 via
`spi_ljca`; `spi1` has no children (`waiting_for_supplier=0`).
* I have not tried a 6.x kernel and many other distros — my recollection is
the camera also did not work on 6.x for me even with the Intel patches, so I
don't think rolling back further is productive.
Attached `diagnostics.txt` (filed initially against 7.0.0-15) and
`diagnostics-7.0.0-14.txt` (captured today on 7.0.0-14) have DMI, package
versions, lsmod, lspci/lsusb, the spi_master tree, the relevant ACPI nodes, and
the IPU6/MEI/VSC/OV2740/LJCA kernel and libcamera/pipewire log lines.
They're the same shape so they can be diffed directly.
- Happy to do whatever's useful: capture across cold-boot/warm-
- boot/suspend cycles, watch whether the INTC1096 GPIO chip ever registers
- across multiple boots, try unbinding/rebinding `usb_ljca`, or run with
- debug options on `int3472`/`mei_vsc`/`gpio_ljca`.
+ Happy to do whatever's useful: capture across cold-boot/warm-boot/suspend
cycles, watch whether the INTC1096 GPIO chip ever registers across multiple
boots, try unbinding/rebinding `usb_ljca`, or run with debug options on
`int3472`/`mei_vsc`/`gpio_ljca`.
+ ---
+ ProblemType: Bug
+ ApportVersion: 2.34.0-0ubuntu2
+ Architecture: amd64
+ AudioDevicesInUse:
+ USER PID ACCESS COMMAND
+ /dev/snd/controlC0: atb 7927 F.... pipewire
+ atb 7941 F.... wireplumber
+ /dev/snd/seq: atb 7927 F.... pipewire
+ CasperMD5CheckResult: pass
+ CurrentDesktop: ubuntu:GNOME
+ DistroRelease: Ubuntu 26.04
+ InstallationDate: Installed on 2026-05-17 (2 days ago)
+ InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64
(20260423.1)
+ MachineType: LENOVO 21E8002YSG
+ Package: linux-image-7.0.0-14-generic 7.0.0-14.14
+ PackageArchitecture: amd64
+ ProcEnviron:
+ LANG=en_US.UTF-8
+ PATH=(custom, no user)
+ SHELL=/bin/bash
+ TERM=xterm-256color
+ XDG_RUNTIME_DIR=<set>
+ ProcFB: 0 i915drmfb
+ ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-7.0.0-14-generic
root=UUID=61e8b5c4-2752-445a-93d2-a68c8bb7dd3c ro quiet splash
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
+ ProcVersionSignature: Ubuntu 7.0.0-14.14-generic 7.0.0
+ Tags: resolute wayland-session
+ Uname: Linux 7.0.0-14-generic x86_64
+ UpgradeStatus: No upgrade log present (probably fresh install)
+ UserGroups: adm cdrom dip lpadmin lxd plugdev sudo users
+ _MarkForUpload: True
+ dmi.bios.date: 12/03/2025
+ dmi.bios.release: 1.33
+ dmi.bios.vendor: LENOVO
+ dmi.bios.version: N3IET53W (1.33 )
+ dmi.board.asset.tag: Not Available
+ dmi.board.name: 21E8002YSG
+ dmi.board.vendor: LENOVO
+ dmi.board.version: SDK0T76530 WIN
+ dmi.chassis.asset.tag: No Asset Information
+ dmi.chassis.type: 10
+ dmi.chassis.vendor: LENOVO
+ dmi.chassis.version: None
+ dmi.ec.firmware.release: 1.21
+ dmi.modalias:
dmi:bvnLENOVO:bvrN3IET53W(1.33):bd12/03/2025:br1.33:efr1.21:svnLENOVO:pn21E8002YSG:pvrThinkPadX1NanoGen2:rvnLENOVO:rn21E8002YSG:rvrSDK0T76530WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21E8_BU_Think_FM_ThinkPadX1NanoGen2:pfaThinkPadX1NanoGen2:
+ dmi.product.family: ThinkPad X1 Nano Gen 2
+ dmi.product.name: 21E8002YSG
+ dmi.product.sku: LENOVO_MT_21E8_BU_Think_FM_ThinkPad X1 Nano Gen 2
+ dmi.product.version: ThinkPad X1 Nano Gen 2
+ dmi.sys.vendor: LENOVO
** Attachment added: "AlsaInfo.txt"
https://bugs.launchpad.net/bugs/2153096/+attachment/5971416/+files/AlsaInfo.txt
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https://bugs.launchpad.net/bugs/2153096
Title:
IPU6 webcam (OV2740) on X1 Nano fails on kernel 7.0.0-14/-15: int3472
cannot find GPIO chip INTC1096:00, VSC chain doesn't come up
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