https://blog.berezovskyi.dev/tags/udev/Recent content in Udev on berezovskyi notesHugoen-usMon, 18 May 2026 00:00:00 +0000https://blog.berezovskyi.dev/notes/dualsense-hidraw-user-switch/Mon, 18 May 2026 00:00:00 +0000https://blog.berezovskyi.dev/notes/dualsense-hidraw-user-switch/<h2 id="the-problem">The Problem</h2> <p>The <a href="https://blog.berezovskyi.dev/notes/linux-multi-seat-gaming-part-3">multi-seat gaming setup</a> runs Steam in a gamescope session as a systemd user service. The machine has two users: the gaming user who owns the gamescope service, and a separate work user. Both users are on seat0. Switching to the work user while the gamescope session is running caused the DualSense controller to stop responding in Steam.</p> <h2 id="why-the-controller-goes-through-hidraw">Why the Controller Goes Through hidraw</h2> <p><a href="https://blog.berezovskyi.dev/notes/linux-multi-seat-gaming-part-3">Part 3</a> explains this in detail. The short version: <code>TemporaryFileSystem=/dev/input</code> in the gamescope service hides all evdev devices from the service process tree. Steam Input bypasses this entirely - it reads the DualSense through <code>/dev/hidraw*</code> (the raw HID interface) for full-feature support: adaptive triggers, haptics, gyro, touchpad. The evdev path is never used.</p>