Ubuntu
u-boot package

20.04.4 candidate image doesn't work with some usb/eth on pi-zero-2

Bug #1961871 reported by Paul Larson
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u-boot (Ubuntu)
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Bug Description

The devices I have at home all seem to work fine, but I noticed on the pi-zero-2 we have in the lab that it was working fine with the armhf candidate image from 20220221 but not with arm64. I was eventually able to get serial console on it and discovered that the device had booted, but failed to detect the network adapter, which in this case is using the r8152 driver and is part of a usb hub.
It's weird that it worked fine on the armhf image but not arm64, so I looked a bit more and found that the arm64 image contained both of these lines in config.txt:
  dtoverlay=dwc2
  dtoverlay=dwc2,dr_mode=host
On armhf, only the second line existed. I commented out the first line with 'dtoverlay=dwc2' and rebooted, then it was able to detect the ethernet-usb dongle and load the drivers for it.

Tags: iso-testing
Revision history for this message
Ubuntu QA Website (ubuntuqa) wrote :

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1961871

tags: added: iso-testing
Revision history for this message
Juerg Haefliger (juergh) wrote (last edit ):

dwc2 is the default for arm64. dtoverlay=dwc2,dr_mode=host is not necessary for pi0. Hrm. That line is actually in the [cm4] section. Are you sure it was loaded?

The daily focal arm64 image from today (20220223) boots fine for me. I also have an r8152 USB NIC attached.

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Juerg Haefliger (juergh) wrote :

Do you have the boot log from the serial console?

Revision history for this message
Juerg Haefliger (juergh) wrote :

Even after adding both lines dtoverlay=dwc2 and dtoverlay=dwc2,dr_mode=host the device boots fine with an r8152 USB NIC attached (and the network comes up).

Can you enable 2nd stage debugging (uart_2ndstage=1 in config.txt)?

You should see on the serial console if the overlay is loaded twice:

MESS:00:00:02.775986:0: brfs: File read: 2129 bytes
MESS:00:00:02.783554:0: brfs: File read: /mfs/sd/overlays/dwc2.dtbo
MESS:00:00:02.795064:0: Loaded overlay 'dwc2'
MESS:00:00:02.808943:0: brfs: File read: 801 bytes
MESS:00:00:02.812798:0: brfs: File read: /mfs/sd/overlays/dwc2.dtbo
MESS:00:00:02.824888:0: Loaded overlay 'dwc2'
MESS:00:00:02.827544:0: dtparam: dr_mode=host

Revision history for this message
Paul Larson (pwlars) wrote :

Here's the serial log with uart_2ndstage=1 in config.txt

Revision history for this message
Paul Larson (pwlars) wrote :

Here's another one with quiet bootsplash turned off and ignore_loglevel on

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Łukasz Zemczak (sil2100) wrote :

Since it's unclear re: what the root cause is, I would release-note it for 20.04.4.

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