Checkbox detect an extra webcam "video1"

[Gene Li]

Summary: System only have 1 webcam (video0) but checkbox detect an extra webcam "video1"

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system-product-name: Latitude 5501
GPU: 00:02.0 VGA compatible controller: Intel Corporation Device 3e9b (rev 02)
CPU: Intel(R) Core(TM) i7-9850H CPU @ 2.60GHz (12x)
bios-version: 1.0.0
system-manufacturer: Dell Inc.
Image: somerville-bionic-amd64-iso-hybrid-20180608-47

[Gene Li (genelicc)]

Automatically attached

[Gene Li (genelicc)]

Automatically attached

[Gene Li (genelicc)]

Automatically attached

[Gene Li (genelicc)]

Automatically attached

[Gene Li (genelicc)]

https://certification.canonical.com/hardware/201903-26914/submission/140202/test/76249/result/10501614/

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Format: (00000032-0002-0010-8000-00aa003)
Resolutions: 340x340

Taking multiple images using the format
Traceback (most recent call last):
  File "/tmp/nest-y_ppt4sw.d1638308f2288bbf538a20989cac250249789e6a17c46fe001795d51e9dcdee2/camera_test", line 588, in <module>
    sys.exit(getattr(camera, args.test)())
  File "/tmp/nest-y_ppt4sw.d1638308f2288bbf538a20989cac250249789e6a17c46fe001795d51e9dcdee2/camera_test", line 365, in resolutions
    suffix='.jpg', delete=False)
  File "/usr/lib/python3.6/tempfile.py", line 688, in NamedTemporaryFile
    (fd, name) = _mkstemp_inner(dir, prefix, suffix, flags, output_type)
  File "/usr/lib/python3.6/tempfile.py", line 399, in _mkstemp_inner
    fd = _os.open(file, flags, 0o600)
ValueError: embedded null byte

[Sylvain Pineau (sylvain-pineau)]

Not a checkbox bug since udev creates two devices for the same camera. found the same problem for Sideswipe:

https://certification.canonical.com/hardware/201902-26860/submission/141671/

It's a cert blocker.

[Betty Lin (bettyl)]

@Sylvain

I found a similar problem when running "video1" with the error:

Traceback (most recent call last):
  File "/tmp/nest-al0bjp_e.79f904e165d58eb488e8c67fd21e8733c7b6bbc5b3fb884068140a5b06b297c8/camera_test", line 588, in <module>
    sys.exit(getattr(camera, args.test)())
  File "/tmp/nest-al0bjp_e.79f904e165d58eb488e8c67fd21e8733c7b6bbc5b3fb884068140a5b06b297c8/camera_test", line 290, in still
    self.args.quiet)
  File "/tmp/nest-al0bjp_e.79f904e165d58eb488e8c67fd21e8733c7b6bbc5b3fb884068140a5b06b297c8/camera_test", line 323, in _still_helper
    still_texture = Clutter.Texture.new_from_file(filename)
GLib.Error: gdk-pixbuf-error-quark: Image file '/tmp/camera_test_0emg6e5y.jpg' contains no data (0)

I figure out Cheese can choose video1 as camera, but checkbox can't.

u@u-Latitude-3590:~$ checkbox-cli --version
checkbox-ng: 1.4.0
checkbox-support: 0.41.0
com.canonical.ce:oem: 1.0
certification-client: 0.37.0
plainbox-provider-checkbox: 0.48.0
plainbox-provider-resource-generic: 0.40.0
plainbox-provider-sru: 1.13.0
plainbox-provider-tpm2: 1.10.0

[Betty Lin (bettyl)]

@Sylvain

For #9, the machine I tested which has four camera devices list in udevadm - video0, video1, video2 and video3.

When running checkbox with those camera devices, only video0 and video2 can pass the tests.

[Jerry Kao (jerry.kao)]

Seems it's normal that udev creates two devices for the same camera as Gene discovered with OEM image 18.04 with OEM kernel 4.15 as stock 18.04.2 and 19.04.

I found the same symptom on 201803-26172 with 18.04.2. Please refer https://paste.ubuntu.com/p/gnszvyrWtR/ and https://paste.ubuntu.com/p/Q7qMtxrwrD/
Also 201810-26509 with 19.04. Please refer https://paste.ubuntu.com/p/PZdcSdHBXD/

For 2 cameras hardware as comment#10, udev creates 4 devices in Bettey's case.

[Taihsiang Ho (tai271828)]

Potentially same bug fyi https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1832239

[Taihsiang Ho (tai271828)]

According to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1832239/comments/3 this is caused by a kernel new feature to dump uvcvideo metadata into another separated video node in userspace.

This issue is not a checkbox bug but I personally more inclined to tweak the device parser of checkbox to meet the new kernel feature.

[Kai-Heng Feng (kaihengfeng)]

IMO it's a bug in checkbox, kernel doesn't do anything wrong.

The metadata device only has capability V4L2_CAP_META_CAPTURE, it doesn't have V4L2_CAP_VIDEO_CAPTURE, which is required for capturing video.

Please see the example in linux kernel doc and modify checkbox accordingly:
https://www.kernel.org/doc/html/latest/media/uapi/v4l/capture.c.html

[Kai-Heng Feng (kaihengfeng)]

Fixed by https://github.com/systemd/systemd/commit/646876105fe1799355715839477958adf1d096fd

[Sylvain Pineau (sylvain-pineau)]

In the goal of teaching the checkbox udev parser how to discard the metadata device node, @Gene and @Betty could you please run this command on all devices listed as video under /dev and mention the CID on the corresponding system?

v4l2-ctl --device=/dev/video0 --all
v4l2-ctl --device=/dev/video1 --all
v4l2-ctl --device=/dev/video2 --all
v4l2-ctl --device=/dev/video3 --all
...

Thanks

[Betty Lin (bettyl)]

@Sylvain
CID: 201711-25942
Video devices information as attached.

[Sylvain Pineau (sylvain-pineau)]

Thanks @Gene, for this system I think it's a combo color + IR webcam for windows hello compatibility.

See https://www.dell.com/en-us/work/shop/cty/pdp/spd/latitude-15-5501-laptop/s009l550115us

"Bypass passwords: Start the workday faster by signing on with an optional fingerprint reader integrated into the power button or with the optional IR camera + Windows Hello for seamless authentication. "

Such webcams are sometimes very well designed and almost invisible in the screen chassis but a closer look can reveal the two sensors. Can you confirm it's a system with two cameras?

[Betty Lin (bettyl)]

Found one new case that got the same error for video 1 with latptop - 201903-26914

[Betty Lin (bettyl)]

Verified the bug pass with latptop - 201903-26914

checkbox-ng: 1.5.0rc3
checkbox-support: 0.42.0rc2
com.canonical.ce:oem: 1.0
certification-client: 0.38.0rc2
plainbox-provider-checkbox: 0.49.0rc4
plainbox-provider-resource-generic: 0.41.0rc2
plainbox-provider-sru: 1.14.0rc1
plainbox-provider-tpm2: 1.11.0rc2

[Dan Streetman (ddstreet)]

please reopen if this is still an issue