May 3, 2026, 3:33pm 1

Hi, I’m running into a really frustrating issue with my DualShock 4 on CachyOS and I’m trying to figure out whether this is a known regression in the Bluetooth / kernel / firmware stack.

The important part is: this same controller worked before on the same hardware under Omarchy, so I do not think the controller itself is broken.

System

• OS: CachyOS

• DE: KDE Plasma 6.6.4

• WM: KWin (Wayland)

• Kernel: 7.0.3-1-cachyos

• Bluetooth chipset: MediaTek (0e8d:0616)

• Board: X670E AORUS MASTER

Package versions

• bluez 5.86-5.1

• bluez-utils 5.86-5.1

• pipewire 1.6.4-1.1

• wireplumber 0.5.14-1.1

• linux-firmware 20260309-1

• linux-cachyos 7.0.3-1

Problem

The real physical DualShock 4 either:

• does not show up reliably during Bluetooth scan,

• or it shows up, pairs/bonds/trusts, but then

• disconnects immediately again.

Sometimes I can get it to the point where BlueZ reports:

• Paired: yes

• Bonded: yes

• Trusted: yes

but it still disconnects right after that.

What makes me think this is not a controller issue

• same controller worked before on the same PC/hardware

• no Sunshine installed

• no obvious virtual PS4 input device

• issue seems to be lower level than Steam / SDL / Proton

Relevant observations

I saw errors like:

• Bluetooth: hci0: command 0xfd98 tx timeout

• Bluetooth: hci0: Failed to apply iso setting (-110)

• repeated btusb / hci0 reinitialization

• immediate disconnects after bonding

There were also cases where:

• the adapter went into off-blocked

• bluetoothctl reported Busy

• bluetoothctl even segfaulted once

Bluetooth device

From lsusb:

• 0e8d:0616 MediaTek Inc. Wireless_Device

Things I already tried

• restarting bluetooth.service

• rfkill unblock bluetooth

• removing and re-pairing device multiple times

• clearing /var/lib/bluetooth/... device cache

• testing with and without disable_ertm

• reloading btusb

• unbind/bind of the USB Bluetooth device

• testing with scan on/off

• testing BR/EDR scan

• checking for Sunshine / virtual HID conflicts

• checking /etc/bluetooth/main.conf

• testing different pairing flows

• verifying uhid / hid_playstation

• trying to stabilize power state / adapter power

Example behavior

Typical flow looks like this:

1. controller appears as Wireless Controller

2. pair may initially fail with AuthenticationFailed

3. after retry / authorization, device can become bonded/trusted/paired

4. connect reports connected briefly

5. device immediately disconnects again

Logs

Relevant kernel / Bluetooth messages include:

• command 0xfd98 tx timeout

• Failed to apply iso setting (-110)

• repeated adapter setup / reset messages on hci0

• MediaTek Bluetooth repeatedly reinitializing

What I want to know

• Is this a known regression with MediaTek Bluetooth on current CachyOS kernel / firmware?

• Has anyone seen this specifically with DualShock 4?

• Is there a known good combination of:

  • linux-cachyos

  • linux-firmware

  • bluez
    for MT7921/MT7922 Bluetooth?

• Would you recommend downgrading kernel and/or firmware?

If needed, I can also post:

• full dmesg

• journalctl -u bluetooth

• rfkill list

• bluetoothctl show

• package/version outputs

• exact pairing logs