[Bug 2163610] Re: OVTI08F4 camera fails to probe on HP Spectre x360 14-eu0xxx (error -121)

Quick update: the Fedora maintainer has now sent a patch upstream that uses a 200 ms post-handshake delay for all sensors. That replaces the HP-only 150 ms workaround I tested here. There is also a Fedora kernel PR, and the related Fedora bug has been reopened until the fix lands. So this is moving in the right direction, but it is not in an Ubuntu kernel yet: https://bugzilla.redhat.com/show_bug.cgi?id=2333331#c104 ** Bug watch added: Red Hat Bugzilla #2333331 https://bugzilla.redhat.com/show_bug.cgi?id=2333331 -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2163610 Title: OVTI08F4 camera fails to probe on HP Spectre x360 14-eu0xxx (error -121) Status in linux package in Ubuntu: New Bug description: I am reporting a built-in camera failure on an HP Spectre x360 2-in-1 Laptop 14-eu0xxx. System - Ubuntu 26.04 LTS - linux-image-7.0.0-29-generic, package version 7.0.0-29.29 - Camera sensor: OVTI08F4 / OmniVision ov08x40 - Intel IPU6 camera stack Expected result The ov08x40 sensor should probe and the built-in camera should be available to libcamera and desktop camera applications. Actual result The sensor fails to read its chip ID and the camera is unavailable: ov08x40: error reading chip-id register: -121 What I found The existing 45 ms INT3472 handshake delay is not long enough on this laptop. A 150 ms delay allows the sensor to probe. I prepared a DMI-scoped quirk so the longer delay is used only for the matching HP Spectre x360 14-eu0xxx family. After the sensor probes, libcamera also needs the ov08x40 driver to report the native size, crop bounds, and active crop through get_selection(). Without that, camera setup fails with rectangle ioctl errors. Testing I applied both kernel patches to the Ubuntu 7.0.12 source from linux-source-7.0.0 package version 7.0.0-29.29 and built the three affected modules for 7.0.0-29-generic. The patches passed scripts/checkpatch.pl --strict. The rebuilt modules were signed for Secure Boot, installed, and loaded after reboot. With the patches applied: - the sensor was detected and the -121 probe error did not return; - libcamera detected one camera and captured 60 consecutive 3848x2416 frames at 30 fps; - PipeWire exposed the built-in front camera; and - GNOME Snapshot showed a stable live preview. Patches and full validation notes https://github.com/liondragon/hp-spectre-ov08x40-camera Kernel patches https://github.com/liondragon/hp-spectre-ov08x40-camera/tree/main/patches/linux Validation record https://github.com/liondragon/hp-spectre-ov08x40-camera/blob/main/docs/validation.md To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2163610/+subscriptions