DISPLAY DRIVER INTEGRATION(9)

🎀 display driver integration(9) — Kernel API Manual edition ✨

okay bestie, welcome to the Kernel API Manual page for display driver integration(9) — this is the whole group-chat lore on how display drivers and bridges link up 🫶

Display drivers are responsible for linking encoders with the first bridge in the chains. How do they do it? By acquiring the appropriate bridge with devm_drm_of_get_bridge. Once acquired, the bridge shall be attached to the encoder with a call to drm_bridge_attach. That's the move 💅

Bridges are responsible for linking themselves with the next bridge in the chain, if any. Same energy as for encoders: this is done with the call to drm_bridge_attach occurring in the drm_bridge_funcs.attach operation.

Once these links are created, the bridges can participate along with encoder functions to perform:

• mode validation and fixup — through drm_bridge_chain_mode_valid and drm_atomic_bridge_chain_check
• mode setting — through drm_bridge_chain_mode_set
• enable — through drm_atomic_bridge_chain_pre_enable and drm_atomic_bridge_chain_enable
• disable — through drm_atomic_bridge_chain_disable and drm_atomic_bridge_chain_post_disable

Those functions call the corresponding operations provided in drm_bridge_funcs in sequence for all bridges in the chain. Literally in sequence for the whole chain, no skipping 😌

For display drivers that use the atomic helpers drm_atomic_helper_check_modeset, drm_atomic_helper_commit_modeset_enables and drm_atomic_helper_commit_modeset_disables — either directly in hand-rolled commit check and commit tail handlers, or through the higher-level drm_atomic_helper_check and drm_atomic_helper_commit_tail or drm_atomic_helper_commit_tail_rpm helpers — this is done transparently and requires no intervention from the driver. Iconic, honestly ✨ For other drivers, the relevant DRM bridge chain functions shall be called manually. You got this 🫡

Bridges also participate in implementing the drm_connector at the end of the bridge chain. Display drivers may use the drm_bridge_connector_init helper to create the drm_connector, or implement it manually on top of the connector-related operations exposed by the bridge (see the overview documentation of bridge operations for more details). Main-character connector energy, fr fr 👑

✨ SEE ALSO ✨

• Kernel file ./drivers/gpu/drm/drm_bridge.c — overview(9)
• special care dsi(9)
• dsi bridge operations(9)
• bridge chain format selection(9)
• drm_bridge_enter(9)
• drm_bridge_exit(9)
• drm_bridge_unplug(9)
• drm_bridge_get(9)
• drm_bridge_put(9)
• drm_bridge_clear_and_put(9)
• drm_bridge_put_void(9)
• drm_bridge_add(9)
• devm_drm_bridge_add(9)
• drm_bridge_remove(9)
• drm_bridge_attach(9)
• bridge operations(9)
• drm_bridge_chain_mode_valid(9)
• drm_bridge_chain_mode_set(9)
• drm_atomic_bridge_chain_disable(9)
• drm_atomic_bridge_chain_post_disable(9)
• drm_atomic_bridge_chain_pre_enable(9)
• drm_atomic_bridge_chain_enable(9)
• drm_atomic_bridge_chain_check(9)
• drm_bridge_detect(9)
• drm_bridge_get_modes(9)
• drm_bridge_edid_read(9)
• drm_bridge_hpd_enable(9)
• drm_bridge_hpd_disable(9)
• drm_bridge_hpd_notify(9)
• of_drm_find_and_get_bridge(9)
• of_drm_find_bridge(9)
• of_drm_get_bridge_by_endpoint(9)
• devm_drm_put_bridge(9)

that's the whole page, bestie — source vibe ./drivers/gpu/drm, dated October 2026 💖✨