Hotplug of Non-discoverable Hardware: Status and Future Directions
summary
Workable device-tree overlays plus a new connector abstraction let non-discoverable add‑ons be described, detected (EPROM on an I²C bus or probing device combinations), and have overlays loaded and removed at runtime; bus extensions cover I²C/SPI cases. DRM changes add a ref‑counted DRM bridge API merged in kernel 6.16, KUnit tests, debugfs visibility, and ongoing conversion of bridge users so bridges can appear/disappear safely. The prototype handles a MIPI‑DSI → LVDS bridge on the addon and is already used in Bootlin and Aush’s test setups; spec debates (export symbols, pinmux) continue.
AI-written summary · about
chapters (17)
- 0:00Hotplug connectors overview
- 3:16Use case and goals
- 10:00Connector driver status
- 15:24I2C/SPI bus extensions
- 18:35Device tree overlay alternatives
- 19:43DRM video output challenges
- 22:42DRM bridge dynamic lifetime
- 27:19DRM bridge reference counting
- 33:02Conclusion and future work
- 34:49Q&A: Detecting add-on boards
- 36:10Q&A: Stacking connectors
- 38:00Q&A: Pinmux for multi-function pins
- 41:18Q&A: FPGA reconfiguration
- 43:05Q&A: I2C device discovery
- 46:17Q&A: Runtime overlay loading
- 48:01Q&A: CSI2 camera interfaces
- 49:03Q&A: Media subsystem limits
related talks
27mStandardizing Linux DRM drivers implementations by interfacing DRM Bridge as a single...
29mNon-discoverable devices in PCI devices
25mDevice-tree overlay feature allows for runtime modification
45mPowering up "discoverable bus-attached" devices on DT-based platforms
40mSecond Source Component Probing on Device Tree Platforms- 40mSecond Source Component Probing on Device Tree Platforms
01h 10mBoF: Devicetree
01h 13mDevice Tree for Dummies!