Conflicting software

Another RGB tool holding a device means Hypercolor gets nothing. Which programs conflict on Linux, Windows, and macOS, and how to detect and resolve it.

Your device shows up in lsusb but Hypercolor cannot connect to it. The most common cause is that another RGB manager got to the device first and is holding it open. Hypercolor gets no connection, and no error the user would naturally see, just silence.

This page covers which programs conflict, how to confirm a conflict is the culprit, and how to resolve it cleanly.

#Why conflicts happen

Hypercolor controls USB devices through two transport paths:

  • USB control / HID / bulk / MIDI transports: these claim the USB interface directly. The kernel allows only one process to hold a claimed interface at a time. A second claimant fails immediately.
  • HIDRAW / HIDAPI transports: these talk through /dev/hidraw* nodes without an exclusive interface claim, but still require a successful open() on the device file. If another process holds an exclusive file descriptor, the open fails with a permission error even when the udev rules are correct.

In both cases the error surfaces in Hypercolor’s logs as TransportError::PermissionDenied or TransportError::IoError, and the device stays in a disconnected state. The transport layer maps the OS error kind, not the message text: permission-denied becomes TransportError::PermissionDenied, a missing node becomes NotFound, a dropped connection becomes Disconnected, and anything else becomes IoError.

The udev rules in 99-hypercolor.rules grant your user permission to open the device node. They do not prevent another process from opening the same node first. Access control and exclusivity are separate concerns.

#Software known to conflict

#openrazer daemon and kernel modules

The openrazer kernel modules (razerkbd, razermouse, razerfirefly, razercore, and others) claim Razer USB devices at kernel driver level, before any userspace process opens a node. The openrazer-daemon then talks to those modules. Both the modules and the daemon must be out of the picture for Hypercolor’s native Razer driver to open the devices.

Hypercolor has its own complete Razer driver and does not need openrazer. If you have openrazer installed, stop and disable it:

# User-scope service (most installations)
systemctl --user stop openrazer-daemon
systemctl --user disable openrazer-daemon

# System-scope service (some distro packages)
sudo systemctl stop openrazer-daemon
sudo systemctl disable openrazer-daemon

Stopping the daemon is often not enough: the kernel modules may still hold the devices. Unload them:

# Unload in dependency order: peripherals first, then core
sudo modprobe -r razerkbd razermouse razermousemat razerfirefly \
               razernaga razerkraken razermug razercore

# Verify they are gone
lsmod | grep razer

To prevent them from reloading at next boot:

echo "blacklist razerkbd
blacklist razermouse
blacklist razermousemat
blacklist razerfirefly
blacklist razernaga
blacklist razerkraken
blacklist razermug
blacklist razercore" | sudo tee /etc/modprobe.d/no-openrazer.conf

sudo update-initramfs -u

After unloading, replug the device so the kernel re-applies the udev ACL. Then run hypercolor devices discover.

#Razer Synapse (Windows)

Razer Synapse holds exclusive HID access to Razer devices on Windows, and Razer is the largest family Hypercolor supports (70 devices), so this is the most common Windows conflict. Quit Synapse from its tray icon, then check Task Manager for Razer services that keep running after the window closes. Once they are stopped, Hypercolor can drive the hardware; run hypercolor devices discover.

#OpenRGB

OpenRGB talks to many of the same USB devices Hypercolor supports. If OpenRGB has already connected to a device, Hypercolor’s scan will fail to open the same interface. Close OpenRGB entirely before starting Hypercolor.

If you want to use OpenRGB for hardware Hypercolor does not yet support natively, configure it as a bridge rather than a parallel controller. The OpenRGB fallback driver lets Hypercolor route output through a running OpenRGB SDK server on port 6742, with explicit ownership partitioning so both tools target different controllers.

#ASUS Aura Sync / Armoury Crate

On Windows, Armoury Crate and Aura Sync claim ASUS HID interfaces and poll the SMBus lighting controllers. Stop the ASUS services (Armoury Crate Service, AsusCertService) in services.msc, or remove the suite with ASUS’s official uninstall tool. The SMBus path on Windows additionally contends through the PawnIO broker, so vendor SMBus tools and Hypercolor must not poll simultaneously.

Under Wine or Proton, Aura Sync binds to ASUS HID and SMBus interfaces using the same device paths that native Linux applications use. Exit the Wine prefix hosting Armoury Crate before launching Hypercolor.

#Corsair iCUE

On Windows, iCUE claims Corsair HID interfaces and keeps background services running after the window closes. Exit iCUE from the tray, stop its services, then restart Hypercolor.

Under Wine or Proton, iCUE claims the same interfaces through the prefix. Exit iCUE or the Proton prefix hosting it, then restart Hypercolor.

#ckb-next

ckb-next-daemon controls Corsair keyboards and mice via the same HID nodes Hypercolor uses. Stop it before running Hypercolor:

systemctl --user stop ckb-next-daemon

#liquidctl

liquidctl primarily handles cooling but can open Corsair or NZXT RGB controllers. If running as a service, stop it:

sudo systemctl stop liquidcfg

#Other RGB managers

SignalRGB, Polychromatic, and similar tools running via Wine or natively follow the same pattern: one owner per USB interface. Whichever application connects first wins; the rest see a failure.

#macOS

Vendor RGB suites are rare on macOS. The usual conflict there is another instance of an open-source tool holding the HID handle; quit the other tool and rescan.

#Diagnosing a conflict

#Step 1: confirm the device is visible to the OS

lsusb

If your device does not appear here, the problem is physical (cable, port, power) or a missing udev rule, not a software conflict. See USB devices for udev setup.

#Step 2: find which process holds the node

# List hidraw nodes and check what has them open
lsof /dev/hidraw* 2>/dev/null | grep -v "^COMMAND"

If lsof names a process, that is the conflict. You can also use fuser for a specific node:

sudo fuser /dev/hidraw0
ps aux | grep <PID>

#Step 3: check for kernel driver attachment

For Razer devices, the kernel module may hold the device even without a userspace process showing in lsof:

lsmod | grep razer

If any razer* modules appear, they are claiming Razer devices at the kernel level. Unload them as described in the openrazer section above.

#Step 4: read Hypercolor’s logs

RUST_LOG=hypercolor_hal=debug just daemon

A conflict typically surfaces as a PermissionDenied transport error, or as a NotFound error when the busy node cannot be selected:

ERROR hypercolor_hal: TransportError::PermissionDenied { detail: "... permission denied ..." }
ERROR hypercolor_hal: hidraw node not found for 1532:XXXX interface 0 ...

See Debugging and diagnostics for the full logging reference and log target list.

#Step 5: run the built-in diagnostics

hypercolor diagnose

# Or via REST
curl -s -X POST http://localhost:9420/api/v1/diagnose | jq

The devices checks report the tracked device-registry count, output-queue health, USB actor display-lane timing, and display-output encoder health.

#Diagnosing on Windows

The same flow works on Windows with different tools:

  1. Find vendor processes with Task Manager, or with Get-Process in PowerShell: Get-Process | Where-Object { $_.Name -match "Razer|iCUE|Armoury|Asus" }
  2. Check services.msc for vendor services (Razer, Corsair, ASUS) and stop them.
  3. Open Device Manager to see which driver has claimed the device.

Steps 4 and 5 (daemon logs and hypercolor diagnose) are identical on every platform.

#Resolving a conflict

The resolution is always the same: only one application can own a USB device interface at a time. Stop the competing software, then let Hypercolor discover the device.

For background daemons:

# openrazer
systemctl --user stop openrazer-daemon

# ckb-next
systemctl --user stop ckb-next-daemon

# liquidcfg
sudo systemctl stop liquidcfg

For GUI applications:

Close the application completely. On Linux, some apps keep a background process alive after the window closes:

pkill openrgb
pkill ArmouryCrate

After stopping the competing software:

Replug the USB device. The kernel re-runs the udev rules and grants Hypercolor the ACL on the device node. Then trigger a rescan:

hypercolor devices discover

Or via the web UI: open the Devices panel and click Scan.

If you want to keep OpenRGB available for hardware Hypercolor does not natively support, configure it as a bridge rather than a parallel controller. The OpenRGB fallback driver lets Hypercolor route output through a running OpenRGB SDK server on port 6742, with explicit ownership partitioning. See OpenRGB fallback.

#SMBus and I2C conflicts ⚡

ASUS motherboard, GPU, and DRAM lighting goes over /dev/i2c-* (SMBus) rather than USB HID. The same exclusive-ownership principle applies: only one process should be issuing SMBus transactions to a controller at a time. Two applications writing to the same I2C address simultaneously corrupt device state: flickering, wrong colors, or the controller locking up.

Running Hypercolor and OpenRGB (or Aura Sync) simultaneously against the same SMBus controllers can corrupt device state. On some ASUS DRAM controllers this requires a physical power cycle to recover.

Check what is accessing your i2c nodes:

lsof /dev/i2c-* 2>/dev/null

If you are running OpenRGB alongside Hypercolor and both are configured to control ASUS Aura hardware, disable SMBus scanning in one of them before enabling SMBus access in Hypercolor. See SMBus and I2C devices for setup details.

#Preventing conflicts on startup

If openrazer or another RGB daemon starts automatically at login, you can stop it before the Hypercolor user service launches using a systemd drop-in:

mkdir -p ~/.config/systemd/user/hypercolor.service.d

Create ~/.config/systemd/user/hypercolor.service.d/stop-openrazer.conf:

[Service]
ExecStartPre=/usr/bin/systemctl --user stop openrazer-daemon

Reload the user manager:

systemctl --user daemon-reload

This runs a best-effort stop before Hypercolor starts and will not fail the service if openrazer is not installed.

On Windows, disable the vendor suite’s autostart entry on Task Manager’s Startup apps page so the vendor tool does not reclaim devices at login.

#Still not connecting?

If you have stopped all competing software and the device still does not appear:

  1. Verify udev rules are installed: ls -la /etc/udev/rules.d/99-hypercolor.rules
  2. Reload rules and replug: sudo udevadm control --reload && sudo udevadm trigger
  3. Check kernel messages: sudo dmesg | grep -i "hid\|usb" | tail -20
  4. See Devices not found for the full device-not-found troubleshooting flow.