[SRU Justification]
[Impact]
Intel IPU6 camera driver includes a test pattern generator for early
stage development before hardware ready. This driver exposes additional
device nodes up to 24 of them as video devices. While Microsoft Teams,
and maybe other video/camera apps as well, tries to locate a suitable
device one by one, this may take up to minutes before returning to a
usable state.
[Fix]
Intel resolved this by removing TPG in their kernel driver release
Release_20210520
(https://github.com/intel/ipu6-drivers/commit/362375c928d184fb0b4187df7da1ffd506bbd07f).
[Test Case]
Before this patch, there are 25 video devices on the testing platform.
One additional is created by v4l2loopback. By removing TPG as this
change does, the remaining video devices should be two exactly:
$ ls -al /dev/video*
crw-rw----+ 1 root video 81, 0 May 25 02:08 /dev/video0
crw-rw---- 1 root video 81, 1 May 25 02:08 /dev/video1
[Where problems could occur]
On this platform TPG is never used after hardware being enabled. So it's
probably pretty safe to remove them.
[Other Info]
While Intel IPU6 driver is currently for oem-5.10 only and there is plan
for newer kernels at the moment, only oem-5.10 is nominated.
========== original bug description ==========
Both of snap and deb of Microsoft Teams apps take minutes to probe all video device nodes before starting up on Intel IPU6 camera platforms. It's rooted in the extra video devices created for IPU6 TPG (test pattern generator), and Intel resolved this by removing TPG in their kernel driver release Release_20210520 (https://github.com/intel/ipu6-drivers/commit/362375c928d184fb0b4187df7da1ffd506bbd07f).
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27.17
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: u 2219 F.... pulseaudio
CasperMD5CheckResult: skip
DistributionChannelDescriptor:
# This is the distribution channel descriptor for the OEM CDs
# For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
canonical-oem-somerville-focal-amd64-20200502-85+fossa-mewtwo+X82
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2021-05-21 (4 days ago)
InstallationMedia: Ubuntu 20.04 "Focal" - Build amd64 LIVE Binary 20200502-05:58
MachineType: Dell Inc. Latitude 9420
Package: linux (not installed)
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.10.0-2026-oem root=UUID=597af0c1-07a4-45f8-9de9-77ca8ed3661d ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 5.10.0-2026.27+lp1926275.1.fix.ov01a1s.iq-oem 5.10.31
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-5.10.0-2026-oem N/A
linux-backports-modules-5.10.0-2026-oem N/A
linux-firmware 1.187.12
Tags: focal
Uname: Linux 5.10.0-2026-oem x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: N/A
_MarkForUpload: True
dmi.bios.date: 02/27/2021
dmi.bios.release: 1.1
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.1.1
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.1.1:bd02/27/2021:br1.1:svnDellInc.:pnLatitude9420:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct10:cvr:
dmi.product.family: Latitude
dmi.product.name: Latitude 9420
dmi.product.sku: 0A32
dmi.sys.vendor: Dell Inc.
apport information