linux-drivers/
drivers/gpu/drm/amd/display/dc/hwss/dcn401

AMD DCN 4.0.1 display hardware sequencer for RDNA 4 GPUs

Display pipeline programming for AMD's DCN 4.0.1 block, the on-chip display controller used by the Radeon RX 9000 (RDNA 4) family of GPUs that AMD launched in February 2025. It handles the low-level sequencing for driving monitors — power-up ordering, pipe and plane setup, link training and similar tasks — on current AMD desktop and workstation graphics cards.

keep conf=0.83 deploy=medium replacement=none subsystem=gpu category=graphics-display
83%

recommendation

It should stay in the kernel because this is the hardware sequencing code for AMD's Display Core Next 4.0.1 block, the display engine in the RDNA 4 generation that AMD launched in early 2025 with the Radeon RX 9000 series. The directory is brand new, sees steady bug-fix and feature commits from multiple AMD authors through 2026, and powers cards still being sold and shipped to Linux users today.

repository signals

4 files
4,466 source lines
119 commits, 5y
+5,587 / −1,121 lines added / removed, 5y
42 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 119 total · active in 25/61 months
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sources

  1. amd.com

    AMD launched RDNA 4 Radeon RX 9000 series in 2025, so the associated display IP is not legacy-only hardware.

  2. amd.com

    Radeon RX 9070 is an actively marketed RX 9000-series product with Linux support, indicating ongoing new-hardware deployment.

  3. dri.freedesktop.org

    Upstream AMDGPU documentation tracks current AMD display/IP generations through 2025-era products, consistent with DCN-family support being active rather than obsolete.

codex reasoning notes (technical)

Shell inspection shows this directory is live hardware-sequencer code for AMD display, not a helper library. Local git log (shell: `git -c safe.directory=... log -- drivers/gpu/drm/amd/display/dc/hwss/dcn401`) shows steady 2024-2026 bug-fix and feature work from many authors, with latest substantive touch on 2026-03-21 and no deprecation/removal-oriented history beyond routine cleanup; a grep for remove/deprecat/obsolete only found normal code cleanup, not retirement discussion. Local ripgrep also shows DCN401/IP_VERSION(4,0,1) integration across amdgpu/display. URLs were obtained via web search/open for AMD official product and press pages plus kernel docs. Recommendation is keep because the code is both newly introduced and under active upstream development for hardware still entering new deployments.