# USB-C bug: port fails to initialize after an unplug/plug

- From: \<hidden\>
- Date: 2021-02-26 20:57:35 
- List: linux-usb
- Page: https://ratatoskr.run/linux-usb/2021/02/8876440
- Thread: https://ratatoskr.run/linux-usb/2021/02/8876440/t.md

```text
I'd like to report a USB-C bug. I recently switched from my linux distro's "stable" 5.4.99 kernel to the "testing" 5.11.2 version. A USB-C problem appeared in the 5.11.2 kernel. When a device is unplugged and then re-plugged back in, it does not initialize and the following message shows up in dmesg:

[ 5082.822133] ucsi_acpi USBC000:00: UCSI_GET_PDOS failed (-95)

This appears to be emitted by the code in drivers/usb/typec/ucsi/ucsi.c

Booting a 5.4.99 kernel makes the issue go away.

If the host is booted up with USB-C devices plugged in, they all come up. It's the unplugging and replugging at runtime that triggers the issue.

Carlos Konstanski

```