** Description changed:

- ## System
+ ## Affected hardware:
  - Machine: Dell Pro Max 16 MC16250
- - BIOS: 1.12.1 (2026-02-12)
- - OS: Ubuntu 24.04 Noble
- - Kernel: 6.17.0-1012-oem (also tested: 6.11.0-1025-oem, same result)
- - OEM meta-package: oem-somerville-gogoat-meta 24.04ubuntu5
- 
- ## Camera hardware
- - Sensor: OmniVision OV08X40 (ACPI: OVTI08F4:00)
+ - Camera: OmniVision OV08X40 (ACPI: OVTI08F4:00)
  - Image path: MIPI CSI-2 → Intel IPU6 (PCI 0000:00:05.0)
  - I2C control: Synaptics SVP7500 USB bridge (06cb:0701) → usbio → i2c-4
- - Camera driver: ov08x40 (in-tree, kernel/drivers/media/i2c/ov08x40.ko.zst)
+ - BIOS: 1.12.1 (Feb 12, 2026) — latest available
+ - Kernel: 6.17.0-1012-oem and 6.11.0-1025-oem (both affected)
+ - OS: Ubuntu 24.04
  
- ## Symptom
- Camera opens and initializes successfully, but output is severely
- distorted with incorrect/neon colors. Affects video calls (Google
- Meet, etc.) and all camera applications.
+ ## Symptom:
+ The camera initialises successfully but produces severely distorted output 
with wrong/neon colours. The issue is reproducible across 4 identical units, 
ruling out per-unit hardware failure.
  
- Confirmed on 3 identical Dell Pro Max 16 MC16250 units, all running
- Ubuntu 24.04 with the same BIOS version.
- 
- ## Kernel errors (when camera is active, ~400/second)
+ ## Kernel errors (when camera is active, ~400/sec):
  intel_ipu6_isys.isys intel_ipu6.isys.40: csi2-0 error: DPHY recoverable 
synchronization error
  intel_ipu6_isys.isys intel_ipu6.isys.40: csi2-0 error: Payload checksum (CRC) 
error
  intel_ipu6_isys.isys intel_ipu6.isys.40: csi2-0 error: Single packet header 
error corrected
  intel_ipu6_isys.isys intel_ipu6.isys.40: csi2-0 error: Multiple packet header 
errors detected
- intel_ipu6_isys.isys intel_ipu6.isys.40: csi2-0 error: Inter-frame long 
packet discarded
  
- ## Camera HAL errors (per frame)
+ The camera HAL confirms every frame is corrupt:
  CamHAL[WAR] <seq0>needQueueBack: buffer error
  CamHAL[WAR] <seq1>needQueueBack: buffer error
- ... (every frame)
+ ...
  
- ## What was tried
- - Switched from out-of-tree ov08x40 (linux-modules-ipu6) to in-tree
- driver (kernel/drivers/media/i2c/ov08x40.ko.zst) — no change
- - Tested kernel 6.11.0-1025-oem — same CSI-2 errors, same distortion
- - All packages are at latest available version (no updates pending)
- - BIOS is at latest version (1.12.1), but the issue was also present in the 
previous BIOS version
+ ## Root cause analysis:
  
- ## Suspicion
- An earlier BIOS version may have changed ACPI camera
- link-frequency or lane-count data read by ipu_bridge, causing a
- MIPI D-PHY link mismatch. Issue is present across all 4 units
- updated to this BIOS, suggesting a systematic regression rather
- than per-unit hardware failure.
+ The CSI-2 D-PHY errors indicate a MIPI link frequency mismatch between
+ the sensor driver and the hardware configuration.
+ 
+ Inspecting the compiled link frequencies in the ov08x40 kernel modules
+ reveals:
+ 
+ - Out-of-tree (linux-modules-ipu6-6.17.0-1012-oem, 
ubuntu/ipu6/ov08x40.ko.zst): contains both 400,000,000 Hz (800 Mbps/lane, 
4-lane) and 749,000,000 Hz (~1500 Mbps/lane, 2-lane)
+ - In-tree (linux-oem-6.17, kernel/drivers/media/i2c/ov08x40.ko.zst): contains 
only 400,000,000 Hz (800 Mbps/lane) — the 2-lane ~1500 Mbps frequency is absent
+ 
+ This hardware appears to use 2 CSI-2 data lanes at ~1500 Mbps/lane. When
+ the in-tree driver is loaded, it only advertises 400 MHz to ipu_bridge,
+ which configures the D-PHY receiver at the wrong speed, causing the
+ observed sync/CRC errors.
+ 
+ Bug #2084059 previously added 2-lane/1500 Mbps support for the OV08X40
+ and was marked fixed in linux-oem-6.11 at version 6.11.0-1007.7, but
+ this fix does not appear to be present in the in-tree ov08x40 driver in
+ linux-oem-6.17.
+ 
+ Bug #2137700 subsequently migrated users from the out-of-tree to the in-tree 
driver due to usbio incompatibility — but as shown above, the in-tree driver is 
missing the 2-lane frequency support needed for this hardware, so the migration 
leaves the
+ camera broken.
+ 
+ ## Troubleshooting steps taken:
+ - Confirmed latest BIOS (1.12.1) — no updates available via fwupd
+ - Tested both kernel 6.17.0-1012-oem and 6.11.0-1025-oem — both affected
+ - Swapped between out-of-tree and in-tree ov08x40 driver — both produce 
identical CSI-2 errors (out-of-tree has 749 MHz but still fails, suggesting the 
ipu_bridge or another component may also need updating)
+ - v4l2loopback confirmed at 0.12.7 (correct rolled-back version per bug 
#2136769)
+ - Camera HAL tuning file confirmed correct: OV08X40_BBG802N3_RG_MTL.aiqb
+ - ACPI GNVS analysis: L1NL (num lanes) at GNVS+0x0651 / phys 0x51CE3651, L1CK 
(MCLK) at GNVS+0x0657 — could not read due to CONFIG_STRICT_DEVMEM; kernel team 
may be able to confirm lane count from ACPI
+ 
+ ## Expected fix:
+ The in-tree ov08x40 driver in linux-oem-6.17 needs the 749,000,000 Hz link 
frequency entry added (matching the out-of-tree driver), equivalent to the fix 
applied in bug #2084059 for linux-oem-6.11.
  
  ## Packages
  linux-modules-ipu6-oem-24.04d: 6.17.0-1012.12
  linux-modules-usbio-oem-24.04d: 6.17.0-1012.12
  gstreamer1.0-icamera: 0~git202509260937.4fb31db~ubuntu24.04.5
  libcamhal-ipu6epmtl: 0~git202506270118.c933525~ubuntu24.04.5
  v4l2-relayd: 0.1.2-0ubuntu3.1
  
- ## Related bugs
- - LP: #2084059 (CSI2 data lanes issue for OVTI08F4)
- - LP: #2137700 (migrate to in-tree ov08x40 driver)
  
  ProblemType: Bug
  DistroRelease: Ubuntu 24.04
  Package: linux-modules-ipu6-oem-24.04d 6.17.0-1012.12
  ProcVersionSignature: Ubuntu 6.17.0-1012.12-oem 6.17.9
  Uname: Linux 6.17.0-1012-oem x86_64
  ApportVersion: 2.28.1-0ubuntu3.8
  Architecture: amd64
  AudioDevicesInUse:
-  USER        PID ACCESS COMMAND
-  /dev/snd/controlC0:  tpater     3333 F.... pipewire
-                       tpater     3337 F.... wireplumber
-  /dev/snd/seq:        tpater     3333 F.... pipewire
+  USER        PID ACCESS COMMAND
+  /dev/snd/controlC0:  tpater     3333 F.... pipewire
+                       tpater     3337 F.... wireplumber
+  /dev/snd/seq:        tpater     3333 F.... pipewire
  CRDA: N/A
  CasperMD5CheckMismatches: ./casper/initrd 
./casper/minimal.standard.live.hotfix.size ./casper/minimal.standard.live.size 
./casper/minimal.manifest ./casper/minimal.standard.manifest 
./casper/minimal.standard.size ./casper/minimal.hotfix.size 
./casper/minimal.standard.live.hotfix.squashfs 
./casper/minimal.standard.hotfix.squashfs ./casper/minimal.standard.hotfix.size 
./casper/minimal.hotfix.squashfs ./casper/minimal.standard.live.manifest 
./casper/minimal.size ./boot/grub/grub.cfg
  CasperMD5CheckResult: fail
  CurrentDesktop: ubuntu:GNOME
  Date: Thu Mar 12 13:54:38 2026
  DistributionChannelDescriptor:
-  # This is the distribution channel descriptor for Ubuntu 24.04 for Dell
-  # For more information see 
http://wiki.ubuntu.com/DistributionChannelDescriptor
-  canonical-oem-somerville-noble-oem-24.04b-20250708-534
+  # This is the distribution channel descriptor for Ubuntu 24.04 for Dell
+  # For more information see 
http://wiki.ubuntu.com/DistributionChannelDescriptor
+  canonical-oem-somerville-noble-oem-24.04b-20250708-534
  InstallationDate: Installed on 2026-03-10 (2 days ago)
  InstallationMedia: Ubuntu OEM 24.04.2 LTS "Noble Numbat" - Release amd64 
(20250708)
  MachineType: Dell Inc. Dell Pro Max 16 MC16250
  ProcEnviron:
-  LANG=C.UTF-8
-  PATH=(custom, no user)
-  SHELL=/usr/bin/zsh
-  TERM=xterm-256color
-  XDG_RUNTIME_DIR=<set>
+  LANG=C.UTF-8
+  PATH=(custom, no user)
+  SHELL=/usr/bin/zsh
+  TERM=xterm-256color
+  XDG_RUNTIME_DIR=<set>
  ProcFB: 0 i915drmfb
  ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-6.17.0-1012-oem 
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash vt.handoff=7
  RelatedPackageVersions:
-  linux-restricted-modules-6.17.0-1012-oem N/A
-  linux-backports-modules-6.17.0-1012-oem  N/A
-  linux-firmware                           20240318.git3b128b60-0ubuntu2.25
+  linux-restricted-modules-6.17.0-1012-oem N/A
+  linux-backports-modules-6.17.0-1012-oem  N/A
+  linux-firmware                           20240318.git3b128b60-0ubuntu2.25
  SourcePackage: linux-oem-6.17
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 02/12/2026
  dmi.bios.release: 1.12
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: 1.12.1
  dmi.board.name: 0CFP7M
  dmi.board.vendor: Dell Inc.
  dmi.board.version: A01
  dmi.chassis.type: 10
  dmi.chassis.vendor: Dell Inc.
  dmi.ec.firmware.release: 1.22
  dmi.modalias: 
dmi:bvnDellInc.:bvr1.12.1:bd02/12/2026:br1.12:efr1.22:svnDellInc.:pnDellProMax16MC16250:pvr:rvnDellInc.:rn0CFP7M:rvrA01:cvnDellInc.:ct10:cvr:sku0CF1:
  dmi.product.family: Dell Pro Max Laptops
  dmi.product.name: Dell Pro Max 16 MC16250
  dmi.product.sku: 0CF1
  dmi.sys.vendor: Dell Inc.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2144008

Title:
  Dell Pro Max 16 MC16250 (OV08X40 / OVTI08F4): Persistent CSI-2 D-PHY
  errors cause severely distorted camera output

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-oem-6.17/+bug/2144008/+subscriptions


-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to