Microbit WebUSB Udev Rule Missing

Bug #1876831 reported by ryan walmsley
This bug affects 1 person
Affects Status Importance Assigned to Milestone
systemd (Ubuntu)

Bug Description

Expected Result: Micro:Bit shows under Web USB devices in chrome as in 19.10
What happened: Micro:bit does not show under Web USB Devices unless Udev rules are added.

I re-installed my computer recently to 20.04 as my SSD Died around the time it came out so decided to use it as a chance to upgrade at the same time.

I noticed when trying to use the WebUSB Feature of the Micro:bit it was no longer detected by chrome (not via the snap and was direct deb) and to confirm this issue I tried on my Ubuntu 19.10 laptop and it detected the micro:bit via webusb no issue.

After looking around I added the Udev rule from the microbit site at https://support.microbit.org/support/solutions/articles/19000105428-webusb-troubleshooting#Linux

and it did start to work under 20.04.

I would call this a bug, as for many users going from where it's working on one version to not on another I suspect I won't be the only user wondering why it isn't working. If it is where Ubuntu 19.10 and 19.04 (and maybe even earlier) worked then I wouldn't be opening this bug.

Thanks -

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: udev 245.4-4ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-28.32-generic 5.4.30
Uname: Linux 5.4.0-28-generic x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: Unity:Unity7:ubuntu
CustomUdevRuleFiles: 50-microbit.rules 60-brother-libsane-type1-inst.rules .50-microbit.rules.swp 70-snap.snapd.rules
Date: Tue May 5 00:13:23 2020
InstallationDate: Installed on 2020-04-26 (8 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
MachineType: Gigabyte Technology Co., Ltd. B450 AORUS M
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-28-generic root=UUID=f28437b5-488a-45d8-b5e1-5e26fb587038 ro quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/08/2018
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F2
dmi.board.asset.tag: Default string
dmi.board.name: B450 AORUS M
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF2:bd08/08/2018:svnGigabyteTechnologyCo.,Ltd.:pnB450AORUSM:pvrDefaultstring:rvnGigabyteTechnologyCo.,Ltd.:rnB450AORUSM:rvrx.x:cvnDefaultstring:ct3:cvrDefaultstring:
dmi.product.family: Default string
dmi.product.name: B450 AORUS M
dmi.product.sku: Default string
dmi.product.version: Default string
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

Revision history for this message
ryan walmsley (ryanteck) wrote :
Revision history for this message
Dan Streetman (ddstreet) wrote :

So, it works without a custom udev rule in 19.10, but does not work without a custom udev rule in 20.04? Just want to confirm my understanding.

Can you paste the output of these commands, from both your 19.10 and 20.04 systems? Run them while you have the 'micro:bit' device connected, of course, and also please remove any custom udev rule(s) you have added and reboot.

$ lsusb -t
$ find /dev/bus/usb -ls

Changed in systemd (Ubuntu):
status: New → Incomplete
Revision history for this message
ryan walmsley (ryanteck) wrote :

Hi Dan,

That is correct, on 19.10 and I believe 19.04 (but I haven't double tested with 04) the device works without any custom udev rules. But on 20.04 it does.

I removed the custom udev rule from my 20.04 system and plugged in the microbit and confirmed it does no longer show. Then took output from the commands you requested.

I'm guessing that it looks like on my laptop it is changing one of the virtual devices and showing with plugdev against one for that device. On my desktop it's not.

Revision history for this message
ryan walmsley (ryanteck) wrote :
Revision history for this message
ryan walmsley (ryanteck) wrote :
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for systemd (Ubuntu) because there has been no activity for 60 days.]

Changed in systemd (Ubuntu):
status: Incomplete → Expired
Dan Streetman (ddstreet)
Changed in systemd (Ubuntu):
status: Expired → New
Revision history for this message
Dan Streetman (ddstreet) wrote :

I believe you have some udev rule, probably located in /lib/udev/rules.d/, that's setting the device group to 'plugdev' so that you can access it - just like your custom rule does in focal. I think you'll have to determine which rule it is so we can check for changes between 19.10 and focal.

Revision history for this message
Dan Streetman (ddstreet) wrote :

please reopen if this is still an issue

Changed in systemd (Ubuntu):
status: New → Invalid
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