UPower "device changed" when iPhone is connected

[Guy Rutenberg]

Hi,

I'm experiencing a weird behavior whenever I have an iPhone connected via
USB to my laptop: It looks like the power source is getting toggled on and
off / battery is resets/refreshs. This behavior repeats itself every 6
seconds (exactly) as long as the iPhone is connected. Some things I noticed:
1. No data is sent between the phone and the computer (sniffed USB bus
using Beagle).
2. No events in dmesg
3. No events in udev
4. Same behavior doesn't occur with other Phones (Androids)
5. It happens with all iPhones I've tested with (iPhone 7, 8, X, XR and
XS), with different iOS versions installed and also in Recovery Mode.
6. It happens regardless of whether the computer is connected to AC and
whether the phone is connected directly to the computer or through a
powered-hub.
7. I've ruled out issues related to the iPhone's power consumption by
comparing the actual mA output on the port when the phone is connected
compared to other devices.

upower --monintor displays repeating lines containing:
[09:22:41.312] device changed:
/org/freedesktop/UPower/devices/line_power_AC
[09:22:41.313] device changed:
/org/freedesktop/UPower/devices/battery_BAT0
[09:22:41.316] device changed:
/org/freedesktop/UPower/devices/battery_BAT1
[09:22:42.402] daemon changed:

(full logs (including --monitor-detail) are available in
https://gist.github.com/guyru/d9d06a623d599fdeaf7ef8d58d3b9623)

(each of these lines repeats multiple times). If I disable UPower
completely:
$ sudo mv /lib/systemd/system/upower.service{,.disabled} && sudo systemctl
daemon-reload
the weird behavior disappears, which makes me think (given all the other
ruled out options) that the issue is with UPower. However, disabling UPower
on a laptop seems like not a good long term solution to this issue.

My system: 4.19.0-6-amd64, Lenovo ThinkPad T470, Debian 10, upower 0.99.10-1


I'll really appreciate any suggestions to what the issue may be, or further
tips to investigate as this issue is very annoying to me.

Thanks,
Guy
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