Public bug reported:

[Impact]
On the Dell Pro Max 16 Premium MA16250 the built-in camera (OmniVision ov08x40, 
ACPI OVTI08F4) is
wired with 2 MIPI CSI-2 lanes at 749 MHz (1500 Mbps). For this configuration 
the ov08x40 driver exposes
two modes: 3856x2176 and 1928x1088 (2x2 binned, mode_1928x1088_regs_1500mbps).

The 1928x1088 mode only delivers ~3.7 fps, while 3856x2176 runs at ~29 fps. 
libcamera (simple pipeline +
software ISP) always selects the smallest sensor mode that fits the requested 
output, so every
WebRTC/browser resolution (640x480, 1280x720, 1920x1080) ends up in the broken 
mode. The camera is
therefore unusable in Teams, Google Meet, etc. without a workaround.

This matches an upstream report on a sibling Dell model (Dell Pro 14 Premium 
PA14260, IPU7 + Intel CVS,
2 lanes @ 1500 Mbps), where the same binned mode produces unusable frames:
  [PATCH 2/2] media: i2c: ov08x40: Do not expose the broken 1928x1088 binned 
mode (2026-09-04)
  https://ratatoskr.run/lkml/2026/09/17514489/t
The patch has not been merged upstream yet (no review replies as of 2026-10-27).

[Hardware / software]
- Dell Pro Max 16 Premium MA16250, SKU 0D33, board 0TMRG5, BIOS 1.13.1 
(2026-08-03)
- Intel Core Ultra 7 265H (Arrow Lake-H), IPU6 PCI 8086:7d19 (subsystem 
1028:0d33)
- Sensor: ov08x40 (OVTI08F4), 2 lanes, link frequency 749 MHz
- Intel CVS (INTC10E0) via linux-modules-vision-generic (intel_cvs), USBIO 
bridge Synaptics SVP7500 (06cb:0701)
- Ubuntu 26.04.1 LTS, kernel 7.0.0-38-generic, libcamera 0.7.0-1ubuntu2
- Secure Boot enabled

[Test case]
1. Stop anything that uses the camera.
2. Request 720p directly from libcamera and measure the frame rate:
     L=/tmp/fps.log
     LIBCAMERA_LOG_LEVELS='*:ERROR,SimplePipeline:DEBUG' timeout -s INT 12 
gst-launch-1.0 -v -e libcamerasrc \
       ! video/x-raw,width=1280,height=720 ! videoconvert \
       ! fpsdisplaysink video-sink=fakesink text-overlay=false sync=false > 
"$L" 2>&1
     grep -oE 'average: [0-9.]+' "$L" | tail -1
     grep -oE 'Picked [^ ]+ .*stream size 1280x720' "$L"
3. Repeat with width=3848,height=2176 (selects the full mode).

Actual:   720p -> "Picked 1928x1088-SGRBG10_1X10" and ~3.7 fps
          3848x2176 -> "Picked 3856x2176-SGRBG10_1X10" and ~28.7 fps
Expected: ~30 fps at 720p (e.g. by not exposing the broken binned mode, so 
libcamera falls back to
          3856x2176 and scales on the GPU)

Exposure/VBLANK are not the cause (VBLANK stays at its default for 30 fps, and 
the result is the same
with AE disabled), and neither is the ISP (GPU and CPU debayer give the same 
~3.7 fps at ~1 % CPU).

[Workaround]
v4l2-relayd + v4l2loopback virtual camera that requests 2560x1440 from 
libcamerasrc (forces the full
mode) and scales down to 1280x720 -> ~29 fps. This works but adds a relay layer 
and CPU load.

[Request]
Please carry the upstream patch above (or an equivalent fix) as SAUCE in the 
Ubuntu kernel for
26.04, similar to the earlier Dell ov08x40 fix (LP: #2146517, "ov08x40 module 
mounted upside down on
a certain DELL platforms"), or backport it once it is merged upstream.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/2172303

Title:
  ov08x40: 1928x1088 binned mode delivers ~3.7 fps on 2-lane Dell Pro
  Max 16 Premium (IPU6 + CVS) – webcam unusable at <=1080p

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