Hi everyone,
I’ve been using an Android phone as a 4G/LTE modem for my home internet, connected to a Raspberry Pi 4 via USB tethering.
Everything worked fine — except for one strange issue:
When the phone battery reached 100%, it would occasionally pop up a "Charging Only" notification, as if the USB cable had been unplugged and replugged. However, the USB tethering connection itself never dropped.
After some research, I found the root cause: USB autosuspend on the Raspberry Pi 4.
Apparently, even when tethering, the Pi’s USB controller may briefly suspend the device when power demands change, triggering this phantom reconnect behavior.
I disabled USB autosuspend by adding this to /boot/cmdline.txt
Rebooted the Pi — issue gone. The tethering link stays stable, and no more annoying "charging only" pop-ups on the phone.
I found this solution thanks to this helpful post:
viewtopic.php?t=115378
Hopefully, this helps others facing the same glitch.
Cheers!
I’ve been using an Android phone as a 4G/LTE modem for my home internet, connected to a Raspberry Pi 4 via USB tethering.
Everything worked fine — except for one strange issue:
When the phone battery reached 100%, it would occasionally pop up a "Charging Only" notification, as if the USB cable had been unplugged and replugged. However, the USB tethering connection itself never dropped.
After some research, I found the root cause: USB autosuspend on the Raspberry Pi 4.
Apparently, even when tethering, the Pi’s USB controller may briefly suspend the device when power demands change, triggering this phantom reconnect behavior.
I disabled USB autosuspend by adding this to /boot/cmdline.txt
Code:
usbcore.autosuspend=-1I found this solution thanks to this helpful post:
viewtopic.php?t=115378
Hopefully, this helps others facing the same glitch.
Cheers!
Statistics: Posted by isimsek — Sat Jul 19, 2025 7:15 pm